Cool Carrot Osmosis

Monday May 2, 2011

The carrot itself is a type of root—it is responsible for conducting water from the soil to the plant. The carrot is made of cells. Cells are mostly water, but they are filled with other substances too (organelles, the nucleus, etc).


We’re going to do two experiments on a carrot: first we’re going to figure out how to move water into the cells of a carrot. Second, we’ll look at how to move water within the carrot and trace it. Last, we’ll learn how to get water to move out of the carrot. And all this has to do with cells!


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Classifying Objects

Monday May 2, 2011

silverwareGrab a handful of buttons. Make sure there are all different kinds and colors.


If you don’t have buttons, use any pile of objects, like matchbox cars, coins, nuts, etc.


Now group the buttons according to size, color, texture, number of holes, shape, etc.


You can do this activity with shells, peanuts, plant leaves, or the back of your desk drawer. Is it easier to organize the non-living or the living things?


Membranes

Monday May 2, 2011

Here’s a fun experiment that shows you how much stuff can pass through a membrane. Scientist call it the  semi-permeability of membranes.


Before we start, take out your science journal and answer this question: What do you think will happen when we stick a piece of celery into a glass of regular water. Anything special?


What if we add a teaspoon of salt to the water? Now do you think anything will happen?
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Newton’s First Law of Motion

Sunday May 1, 2011
First Law of Motion: Objects in motion tend to stay in motion unless acted upon by an external force. Force is a push or a pull, like pulling a wagon or pushing a car. Gravity is a force that attracts things to one another. Gravity accelerates all things equally. Which means all things speed up the same amount as they fall.

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Newton’s Second Law of Motion

Sunday May 1, 2011
Second Law of Motion: Momentum is conserved. Momentum can be defined as mass in motion. Something must be moving to have momentum. Momentum is how hard it is to get something to stop or to change directions. A moving train has a whole lot of momentum. A moving ping pong ball does not. You can easily stop a ping pong ball, even at high speeds. It is difficult, however, to stop a train even at low speeds.

Materials: garden hose connected to a water faucet

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Newton’s Third Law of Motion

Sunday May 1, 2011
Third Law of Motion: For every action, there is an equal and opposite reaction.

Force is a push or a pull, like pulling a wagon or pushing a car. Gravity is a force that attracts things to one another. Weight is a measure of how much gravity is pulling on an object.

Gravity accelerates all things equally. Which means all things speed up (accelerate) the same amount as they fall. Acceleration is the rate of change in velocity. In other words, how fast is a change in speed and/or a change in direction happening.

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Maxwell’s First Equation

Sunday May 1, 2011

Maxwell’s First Equation: Like charges repel; opposites attract. The proton has a positive charge, the neutron has no charge (neutron, neutral get it?) and the electron has a negative charge. These charges repel and attract one another kind of like magnets repel or attract. Like charges repel (push away) one another and unlike charges attract one another. Generally things are neutrally charged. They aren’t very positive or negative, rather have a balance of both.


Materials: balloon


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Maxwell’s Second Equation

Sunday May 1, 2011

Maxwell’s Second Equation: All magnets have two poles. Magnets are called dipolar which means they have two poles. The two poles of a magnet are called north and south poles. The magnetic field comes from a north pole and goes to a south pole. Opposite poles will attract one another. Like poles will repel one another.


Materials: magnet you can break or cut in half, scissors or hammer (depending on the size of your magnet)


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Maxwell’s Third Equation

Sunday May 1, 2011

Maxwell’s Third Equation: Invisible magnetic fields exert forces on magnets AND invisible electrical fields exert forces on objects. A field is an area around a electrical, magnetic or gravitational source that will create a force on another electrical, magnetic or gravitational source that comes within the reach of the field. In fields, the closer something gets to the source of the field, the stronger the force of the field gets. This is called the inverse square law.


Materials: balloon, magnet, small objects like paper clips or iron filings


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Maxwell’s Fourth Equation

Sunday May 1, 2011

Maxwell’s Fourth Equation: Moving electrical charges (fields) generate magnetic fields AND changing magnetic fields generate electrical fields (electricity). We’re going to do a couple of experiments to illustrate both of these concepts.


Magnetic fields are created by electrons moving in the same direction. A magnetic field must come from a north pole of a magnet and go to a south pole of a magnet (or atoms that have turned to the magnetic field.) Iron and a few other types of atoms will turn to align themselves with the magnetic field. Compasses turn with the force of the magnetic field.


If an object is filled with atoms that have an abundance of electrons spinning in the same direction, and if those atoms are lined up in the same direction, that object will have a magnetic force.


Materials: magnet wire, nail, magnet, compass, 12VDC motor, bi-polar LED, D-cell battery, sandpaper


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Wave-Particle Duality of Light

Sunday May 1, 2011

Light acts like both a particle and a wave, but never both at the same time. But you need both of these concepts in order to fully describe how light works.


Energy can take one of two forms: matter and light (called electromagnetic radiation). Light is energy in the form of either a particle (like a marble) or a wave that can travel through space and some kinds of matter (like a wave on the ocean). You really can’t separate the two because they actually complement each other.


Low electromagnetic radiation (called radio waves) can have wavelengths longer than a football field, while high energy (gamma rays) can destroy living tissue. Light has wavelength (color), intensity (brightness), polarization (the direction of the waves that make up the light), and phase.


Materials: sink or bowl of water, glow in the dark toy, camera flash or sunlight


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Mass is Conserved

Sunday May 1, 2011

A fundamental concept in science is that mass is always conserved. Mass is a measure of how much matter (how many atoms) make up an object. Mass cannot be created or destroyed, it can only change form.


Materials: paper, lighter or matches with adult help


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First Law of Thermodynamics

Sunday May 1, 2011

First Law of Thermodynamics: Energy is conserved. Energy is the ability to do work. Work is moving something against a force over a distance. Force is a push or a pull, like pulling a wagon or pushing a car. Energy cannot be created or destroyed, but can be transformed.


Materials: ball, string


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Second Law of Thermodynamics

Sunday May 1, 2011

Second Law of Thermodynamics: Heat flows from hot to cold. Heat is the movement of thermal energy from one object to another. Heat can only flow from an object of a higher temperature to an object of a lower temperature. Heat can be transferred from one object to another through conduction, convection and radiation.


Temperature is basically a speedometer for molecules. The faster they are wiggling and jiggling, the higher the temperature and the higher the thermal energy that object has. Your skin, mouth and tongue are antennas which can sense thermal energy. When an object absorbs heat it does not necessarily change temperature.


Materials: hot cup of cocoa


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Ideal Gas Law

Sunday May 1, 2011

Pure substances all behave about the same when they are gases. The Ideal Gas Law relates temperature, pressure, and volume of these gases in one simple statement: PV = nRT where P = pressure, V = volume, T = temperature, n = number of moles, and R is a constant.


When temperature increases, pressure and volume increase. Temperature is basically a speedometer for molecules. The faster they are wiggling and jiggling, the higher the temperature and the higher the thermal energy that object has. Pressure is how many pushes a surface feels from the motion of the molecules.


Materials: balloon, freezer, tape measure (optional)


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States of Matter

Sunday May 1, 2011

There are three primary states of matter: solid, liquid, and gas.


Solids are the lowest energy form of matter on Earth. Solids are generally tightly packed molecules that are held together in such a way that they can not change their position. The atoms in a solid can wiggle and jiggle (vibrate) but they can not move from one place to another. The typical characteristics that solids tend to have are that they keep their shape unless they are broken and they do not flow.


Liquids have loose, stringy bonds between molecules that hold molecules together but allow them some flexibility. Liquids will assume the shape of the container that holds it.


Gases have no bonds between the molecules. Gases can be squished (compressed), and pure gases all behave the same way. (We’re going to learn more about this with the Ideal Gas Law.)


Materials: can of soda or glass of water


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Basic Chemistry Safety Information

Monday November 1, 2010

Chemical Data & Safe Handling Information Sheet

What do I really need to know first? First of all, the chemicals in this set should be stored out of reach of pets and children. Grab the chemicals right now and stuff them in a safe place where accidents can’t happen. Do this NOW!


If you haven’t already done so, make sure to watch the introductory video for the Intermediate Chemistry and Advanced Chemistry lessons. They contain important information about the chemicals and lab equipment you’ll be using. When you’re done storing your chemicals out of reach, watch this video:


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Making Litmus Solution and Paper

Sunday October 31, 2010

You can go your whole life without paying any attention to the chemistry behind acids and bases. But you use acids and bases all the time! They are all around you. We identify acids and bases by measuring their pH.


Every liquid has a pH. If you pay particular attention to this lab, you will even be able to identify most acids and bases and understand why they do what they do. Acids range from very strong to very weak. The strongest acids will dissolve steel. The weakest acids are in your drink box. The strongest bases behave similarly. They can burn your skin or you can wash your hands with them.


Acid rain is one aspect of low pH that you can see every day if you look for it. This is a strange name, isn’t it? We get rained on all the time. If people were dissolving, if the rain made their skin smoke and burn, you’d think it would make headlines, wouldn’t you? The truth is acid rain is too weak to harm us except in very rare and localized conditions. But it’s hard on limestone buildings.


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Energy from Sugar

Sunday October 31, 2010

This experiment is for advanced students.


Purple and white colors, making the whitewash that Tom Sawyer used, and produce an exothermic chemical reaction…..does it get any better?


Limewater is one of the compounds we work with in this experiment. Limewater was used in the old days of America. We’re talking about the 80’s…..the 1880’s.


Traveling medicine shows sold what was called “patent medicines”. These usually had no medicinal properties at all. The man in charge, the salesman of the operation, was called a “huckster”. He would have the one of the people gathered around to listen to him blow into limewater. Their exhaled breath contains carbon dioxide, and the lime water turned cloudy, just like in our experiment.


The man would hold up the glass with the cloudy limewater in it and pour in some of his fantastic remedy. As long as the “medicine” was acidic, it would turn the cloudy limewater clear. This was proof that the remedy would cure whatever ailed the person.


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Getting Air from Water

Sunday October 31, 2010

This experiment is for advanced students. This is a repeat of the experiment: Can Fish Drown? but now we’re going to do this experiment again with your new chemistry glassware.


The aquarium looked normal in every way, except for the fish. They were breathing very fast and sinking head first to the bottom of the tank. They would sink a few inches, then jerk into proper movement again.


The student had to figure out what was wrong. He had set up the aquarium as an ongoing science project, and it was his responsibility to maintain the fish tank. His grade depended on it.


He went to his mom for help. She looked over the setup. “Have you tested the water?”


A quizzical look on his face, the boy said, “Everything is normal nitrates, nitrites, hardness, alkalinity, and pH. The pH was a little acidic, but not outside the proper range.”


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Working with Cataylsts

Sunday October 31, 2010

This experiment is for advanced students.


Don’t put this in your car….yet. Hydrogen generation, capture, and combustion are big deals right now. The next phase of transportation, and a move away from fossil fuels in not found in electric cars. Electric cars are waiting until hydrogen fuel cell vehicles become practical. It can be done and is being done.


Cars being powered by hydrogen are here, but not on the market yet. Engineers and chemists are always finding new ways to improve the chemical reaction that produces hydrogen and making the vehicles more efficiently use the fuel. Hydrogen fuel is not just easy to make, it is inexpensive, and the “exhaust” is water.


We will generate hydrogen in this lab. We will also see how combustible it is. Just let your imagination wander….just a bit and you will see noiseless cars and trucks zipping along the streets and interstates, carrying people and cargo. The Indianapolis 500 wouldn’t be quite the same, though. “And there they go, roaring, I mean quietly entering turn two…”


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Hydrogen Peroxide

Sunday October 31, 2010

This experiment is for advanced students.


In industry, hydrogen peroxide is used in paper making to bleach the pulp before they form it into paper. Biologists, when preparing bones for display, use peroxide to whiten the bones.


At home, 3% peroxide combined with ammonium hydroxide is used to give dark-haired people their desired blonde moment. Peroxide is also used on wounds to clean them and remove dead tissue. Peroxide slows the flow from small blood vessels and oozing in wounds as well.


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Generating Oxygen

Sunday October 31, 2010

This experiment is for advanced students.


This time we’re going to use a lot of equipment… really break out all the chemistry stuff. We’ll need all this stuff to generate oxygen with potassium permanganate (KMNO4). We will work with this toxic chemical and we will be careful…won’t we?


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Detonating Bubbles

Sunday October 31, 2010

This experiment is for advanced students.


Zinc (Zn), is a metal and it is found as element #30 on the periodic table. We need a little zinc to keep our bodies balanced, but too much is very dangerous.


Zinc is just like the common, everyday substance that we all know as di-hydrogen monoxide (which is the chemical name for water). We need water to survive, but too much will kill us.


DHMO: In chemistry, “Di” equals the number 2; hydrogen is H; mono equals the number one; and oxide is derived from oxygen, and its symbol is O. Put these together and you have Di-hydrogen (H2), and mono oxygen (O). Put them together, what do you have? Water!


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Desalination

Sunday October 31, 2010

This experiment is for advanced students.


Lewis and Clark did this same experiment when they reached the Oregon coast in 1805. Men from the expedition traveled fifteen miles south of the fort they had built at the mouth of the Columbia River to where Seaside, Oregon now thrives.


In 1805, however, it was just men from the fort and Indians. They built an oven of rocks. For six weeks, they processed 1,400 gallons of seawater, boiling the water off to gain 28 gallons of salt.


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Cold Light

Sunday October 31, 2010

This experiment is for advanced students.


Glo-sticks! Parents hang them from their trick or treaters, backpackers read with them light late at night in a tent. Glo-sticks work on the principle of chemiluminescence.  Chemiluminescence is defined as emitting light without heat as the result of a chemical reaction.


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Carbon Dioxide

Sunday October 31, 2010

This experiment is for advanced students. This lab builds on concepts from the previous carbon dioxide lab.


Limewater….carbon dioxide…indicators. We don’t know too much about these things. Sure, we know a little. Carbon dioxide is exhaled by us and plants need it to grow. Burning fossil fuels produces carbon dioxide.


Indicators…something we observe that confirms to us that something specific is happening. Lime water turns cloudy and forms a precipitate in the presence of carbon dioxide. Blue litmus paper turns red in the presence of an acid. The dog barking at the door and dancing around indicates that you better let the dog out, and quick, to avoid….a pet spill?


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Zinc Dust

Sunday October 31, 2010

This experiment is for advanced students.


Who gets to burn something today? YOU get to burn something today!


You will be working with Zinc (Zn). Other labs in this kit allow us to burn metal, but there is a bit of a twist this time. We will be burning a powder.


Why a powder instead of a solid ribbon or foil as in the other labs?  Have you heard of surface area being a factor in a chemical reaction? The more surface area there is to burn, the more dramatic the chemical change. So, with this fact in mind, a powder should burn faster or be more likely to burn than a large solid.


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Magnesium Battery

Sunday October 31, 2010

Magnesium is one of the most common elements in the Earth’s crust. This alkaline earth metal is silvery white, and soft. As you perform this lab, think about why magnesium is used in emergency flares and fireworks. Farmers use it in fertilizers, pharmacists use it in laxatives and antacids, and engineers mix it with aluminum to create the BMW N52 6-cylinder magnesium engine block. Photographers used to use magnesium powder in the camera’s flash before xenon bulbs were available.


Most folks, however, equate magnesium with a burning white flame. Magnesium fires burn too hot to be extinguished using water, so most firefighters use sand or graphite.


We’re going to learn how to (safely) ignite a piece of magnesium in the first experiment, and next how to get energy from it by using it in a battery in the second experiment. Are you ready?


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Burning Sulfur

Sunday October 31, 2010

This experiment is for advanced students.


Brimstone is another name for sulfur, and if you’ve ever smelled it burn…..whoa….I’m telling you ….you will see for yourself in this lab. It is quite a smell, for sure. Sulfur is element #6 on the periodic table. Sulfur is used in fertilizer, black powder, matches, and insecticides. In pioneer times sulfur was put into patent medicines and used as a laxative.


To further the evil reputation of sulfur, or brimstone, when sulfur is burned in a coal fired power plant, sulfur dioxide is produced. The sulfur is spewed into the air, where it is reacts with moisture in the air to form sulfuric acid. The clouds get full and need to let go of this sulfuric acid. Down comes the acid rain to wreak havoc on the masonry and plant life below.


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Making Copper

Sunday October 31, 2010

In this lab, we’re going to investigate the wonders of electrochemistry. Electrochemistry became a new branch of chemistry in 1832, founded by Michael Faraday. Michael Faraday is considered the “father of electrochemistry”. The knowledge gained from his work has filtered down to this lab. YOU will be like Michael Faraday. I imagined he would have been overjoyed to do this lab and see the results. You are soooo lucky to be able to take an active part in this experiment. Here’s what you’re going to do…


You will be “creating” metallic copper from a solution of copper sulfate and water, and depositing it on a negative electrode. Copper is one of our more interesting elements. Copper is a metal, and element 29 on your periodic table. It conducts heat and electricity very well.


Many things around you are made of copper. Copper wire is used in electrical wiring. It has been used for centuries in the form of pipes to distribute water and other fluids in homes and in industry. The Statue of Liberty is a wonderful example of how beautiful 180,000 pounds of copper can be. Yes, it is made of copper, and no, it doesn’t look like a penny…..on the surface. The green color is copper oxide, which forms on the surface of copper exposed to air and water. The oxide is formed on the surface and does not attack the bulk of the copper. You could say that copper oxide protects the copper.


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Making Chlorine

Sunday October 31, 2010

If we don’t have salt, we die. It’s that simple. The chemical formula for salt is NaCl. Broken down, we have Na (sodium) and Cl (chlorine). Either one of these can be fatal in sufficient quantities. When chemically combined, these two deadly elements become table salt. What once could kill now keeps us alive. Isn’t chemistry awesome?


Chlorine, element 17, is called a halogen as are all the elements in the 17th row. All halogens have similar chemical properties. They are highly reactive nonmetals, and react easily with most metals. Sodium is a metal, and is bonded with sodium in the table salt used in this lab. Besides being found in salt, chlorine has many uses in our world such as killing bacteria in our water, making plastic, cleaning products, and the list goes on. A very useful chemical, and is among the top ten chemicals produced in the United States. Ever since its discovery in 1774, chlorine has been very useful. It is found in nature in sodium chloride, but in very small concentrations. Seawater, the most abundant source of chlorine, has a concentration of only 19g of chlorine per liter.


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Electrochemistry

Sunday October 31, 2010

Electricity. Chemistry. Nothing in common, have nothing to do with each other. Wrong! Electrochemistry has been a fact since 1774. Once electricity was applied to particular solutions, changes occurred that scientists of the time did not expect.


In this lab, we will discover some of the same things that Farraday found over 300 years ago. We will be there as things tear apart, particles rush about, and the power of attraction is very strong. We’re not talking about dancing, we’re talking about something much more important and interesting….we’re talking about ELECTROCHEMISTRY!


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Ammonia Experiments

Sunday October 31, 2010

Ammonia has been used by doctors, farmers, chemists, alchemists, weightlifters, and our families since Roman times. Doctors revive unconscious patients, farmers use it in fertilizer, alchemists tried to use it to make gold, weightlifters sniff it into their lungs to invigorate their respiratory system and clear their heads prior to lifting tremendous loads. At home, ammonia is used to clean up the ketchup you spilled on the floor and never cleaned up.


The ammonia molecule (NH3) is a colorless gas with a strong odor – it’s the smell of freshly cleaned floors and windows. Mom is not cleaning with straight ammonia (it’s gas at room temperature because it boils at -28oF, so the stuff she cleans with is actually ammonium hydroxide, a solution of ammonia and water).  Ammonia is found when plans and animals decompose, and it’s also in rainwater, volcanoes, your kidneys (to neutralize excess acid), in the ocean, some fertilizers, in  Jupiter’s lower cloud decks, and trace amounts are found in our own atmosphere (it’s lighter than air).


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Acids and Bases

Sunday October 31, 2010

This experiment is for advanced students.


ACID!!! The word causes fear to creep in and get our attention.


BASIC!!! The word causes nothing to stir in most of us.


The truth is, a strong acid (pH 0-1) is dangerous, but a strong basic (pH 13-14) is just as dangerous. In this lab, we will get comfortable with the basics of bases and the acidity of acids along with how you can use both and tell the difference between them.


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Making Sodium Hydroxide

Sunday October 31, 2010

This experiment is for advanced students.


Ever use soap? Sodium hydroxide (NaOH) is the main component in lye soap. NaOH is mixed with some type of fat (vegetable, pig, cow, etc).  Scent can be added for the ‘pretty’ factor and pumice or sand can be added for the manly “You’re coming off my hands and I’ll take no guff” factor. Lots of people still make their own soap and they enjoy doing it.


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Potassium Permanganate

Sunday October 31, 2010

This experiment is for advanced students.


Potassium permanganate (KMnO4) in water turns an intense, deep, purple. It is important in the film industry for aging props and clothing to make them look much older than they are.


Also, artists use it in bone carving. People who carve antlers and bone use KMnO4 to darken the surface of the bone to make it look aged. They make the carving, soak it in potassium permanganate, then carve more, and repeat. The end result is a carving that has a light golden brown color. More dipping will darken the carving even more.


Potassium permanganate is going to undergo a chemical change with this activity. In this experiment, we will be able to witness several indicators of chemical change. Color changes, bubbles from gas generation, temperature change, and color disappearance are all indicators of chemical changes.


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Potassium Hexacynoferrate (Reagant)

Sunday October 31, 2010

This experiment is for advanced students.


How do you know if your brother is stealing your candy? Unwrap a wrapped hard candy that he likes a lot. Roll the candy around in the powdered food dye that matches the candy. (Push the powder into the candy so it “disappears”.) Re-wrap the candy. Set the candy in the place where it usually disappears from. Wait ten minutes after the candy disappears. Find your brother. He will be sporting a new color on his hands and mouth. Dye is hard to remove. It will have to be worn every day at school until it fades away as the skin cells slough off. The dye he now wears is in indicator that he has been taking your candy.


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Iron Sparklers

Sunday October 31, 2010

This experiment is for advanced students.


Sparks flying off in all directions…that’s fun. In this lab, we will show how easy it is to produce those shooting sparks. In a sparkler you buy at the store, the filings used are either iron or aluminum.


The filings are placed in a mixture that, when dry, adheres to the metal rod or stick that is used in making the sparkler. The different colors are created by adding different powdered chemicals to the mixture before it dries. When they burn, we get red, blue, white, and green.


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Iodine

Sunday October 31, 2010

This experiment is for advanced students.


In gas form, element #59 is deadly. However, when iodine is in  liquid form, it helps heal cuts and scrapes. The iodine molecule occurs in pairs, not as a single atom (many halogens do this, and it’s called a diatomic molecule). It’s hard to find iodine in nature, though it’s essential for staying healthy… too little iodine in the body takes a heavy toll on how well the brain operates.


A chunk of iodine is blackish-blue, and will sublimate (go from a solid straight to a gas, as seen in the photo here).  Iodine is the heaviest element needed by living things. Iodized salt is sodium chloride fortified with iodine to prevent people from not getting enough iodine in their daily diets.


Iodine is found in seaweed (kelp) and seafood as well as vegetables that are grown in dirt that has high iodine levels. People that live inland and do not eat fish often have lower iodine levels than their coastal, fish-eating neighbors. The trick is not to get too much or too little iodine in your diet, because the symptoms of deficiency and excess levels are quite similar.


Starch (like cornstarch) are used as an indicator for detecting iodine in chemistry experiments. When combined with iodine, starch forms a blue-black color in the solution. We’re going to do this and many other activities in this lab, because this experiment is actually several labs rolled into one. First, we have to make iodine, store it, and then we get to use it in several experiments. Are you ready?


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How to Get Hydrogen from Zinc

Sunday October 31, 2010

This experiment is for advanced students.


Zinc and Hydrogen are important elements for all of us. Zinc (Zn) metal is element #30 on the periodic table. Lack of zinc in our diets will delay growth of our bodies and can kill.


Hydrogen gas (H) is element #1 on the periodic table. Hydrogen was discovered in the 1500s. In a pure state, hydrogen combustion (in small quantities) is interesting. In large amounts, mixed with oxygen, the explosion can be devastating.


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Hydrogen Bromide

Sunday October 31, 2010

WARNING!! THIS EXPERIMENT IS PARTICULARLY DANGEROUS!! (No kidding.) This experiment is for advanced students.


We’ve created a video that shows you how to safely do this experiment, although if you’re nervous about doing this one, just watch the video and skip the actual experiment.


Bromine is a particularly nasty chemical, so be sure to very carefully follow the steps we’ve outlined in the video. You MUST do this experiment outdoors. We’ll be making a tiny amount to show how the chemical reactions involving bromine work.


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Hydrogen Chlorine Gas

Sunday October 31, 2010

WARNING!! THIS EXPERIMENT IS PARTICULARLY DANGEROUS!! (No kidding.) This experiment is for advanced students.


We’ve created a video that shows you how to safely do this experiment, although if you’re nervous about doing this one, just watch the video and skip the actual experiment.


The gas you generate with this experiment is lethal in large doses, so you MUST do this experiment outdoors.  We’ll be making a tiny amount to show how the chemical reactions of chlorine and hydrogen work.


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Fire-Water Balloon

Sunday September 5, 2010

If you’ve ever had a shot, you know how cold your arm feels when the nurse swipes it with a pad of alcohol. What happened there? Well, alcohol is a liquid with a fairly low boiling point. In other words, it goes from liquid to gas at a fairly low temperature. The heat from your body is more then enough to make the alcohol evaporate.


As the alcohol went from liquid to gas it sucked heat out of your body. For things to evaporate, they must suck in heat from their surroundings to change state. As the alcohol evaporated you felt cold where the alcohol was. This is because the alcohol was sucking the heat energy out of that part of your body (heat was being transferred by conduction) and causing that part of your body to decrease in temperature.


As things condense (go from gas to liquid state) the opposite happens. Things release heat as they change to a liquid state. The water gas that condenses on your mirror actually increases the temperature of that mirror. This is why steam can be quite dangerous. Not only is it hot to begin with, but if it condenses on your skin it releases even more heat which can give you severe burns. Objects absorb heat when they melt and evaporate/boil. Objects release heat when they freeze and condense.


Do you remember when I said that heat and temperature are two different things? Heat is energy – it is thermal energy. It can be transferred from one object to another by conduction, convection, and radiation. We’re now going to explore heat capacity and specific heat. Here’s what you do:


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Convection Currents

Sunday September 5, 2010

Every time I’m served a hot bowl of soup or a cup of coffee with cream I love to sit and watch the convection currents. You may look a little silly staring at your soup but give it a try sometime!


Convection is a little more difficult to understand than conduction. Heat is transferred by convection by moving currents of a gas or a liquid. Hot air rises and cold air sinks. It turns out, that hot liquid rises and cold liquid sinks as well.


Room heaters generally work by convection. The heater heats up the air next to it which makes the air rise. As the air rises it pulls more air in to take its place which then heats up that air and makes it rise as well. As the air get close to the ceiling it may cool. The cooler air sinks to the ground and gets pulled back near the heat source. There it heats up again and rises back up.


This movement of heating and cooling air is convection and it can eventually heat an entire room or a pot of soup. This experiment should allow you to see convection currents.


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Sensing Temperature

Sunday September 5, 2010

Temperature is a way of talking about, measuring, and comparing the thermal energy of objects.


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Balloon Gymnastics

Sunday September 5, 2010

Is it warmer upstairs or downstairs? If you’re thinking warm air rises, then it’s got to be upstairs, right? If you’ve ever stood on a ladder inside your house and compared it to the temperature under the table, you’ve probably felt a difference.


So why is it cold on the mountain and warm in the valley? Leave it to a science teacher to throw in a wrench just when you think you’ve got it figured out. Let’s take a look at whether hot air or cold air takes up more space. Here’s what you do:


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Homemade Thermostat

Sunday September 5, 2010

If you can remember thermostats before they went ‘digital’, then you may know about bi-metallic strips – a piece of material made from of two strips of different metals which expand at different rates as they are heated (usually steel and copper). The result is that the flat strip bends one way if heated, and in the opposite direction if cooled.


Normally, it takes serious skill and a red-hot torch to stick two different metals together, but here’s a homemade version of this concept that your kids can make using your freezer.  Here what you do:


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Ghost Coin

Sunday September 5, 2010

This spooky idea takes almost no time, requires a dime and a bottle, and has the potential for creating quite a stir in your next magic show.  The idea is basically this: when you place a coin on a bottle, it starts dancing around. But there’s more to this trick than meets the scientist’s eye.


Here’s how you do it:


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Solar Drinking Bird

Sunday September 5, 2010


The Drinking Bird is a classic science toy that dips its head up and down into a glass of water. It’s filled with a liquid called methylene chloride, and the head is covered with red felt that gets wet when it drinks. But how does it work? Is it perpetual motion?


Let’s take a look at what’s going on with the bird, why it works, and how we’re going to modify it so it can run on its own without using any water at all!


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Hero Engine

Sunday September 5, 2010

There are lots of different kids of heat engines, from stirling engines to big jet turbines to the engine in your car. They all use clever ways to convert a temperature difference into motion.


Remember that the molecules in steam move around a lot faster than in an ice cube. So when we stick hot steam in a container, we can blow off the lid (used with pistons in a steam engine). or we can put a fan blade in hot steam, and since the molecules move around a lot, they start bouncing off the blade and cause it to rotate (as in a turbine). Or we can seal up hot steam in a container and punch a tiny hole out one end (to get a rocket).


One of the first heat engines was dreamed up by Hero of Alexandria called the aeolipile. The steam is enclosed in a vessel and allowed to jet out two (or more) pipes. Although we’re not sure if his invention ever made it off the drawing board, we do know how to make one for pure educational (and entertainment) purposes.  Are you ready to have fun?


THIS EXPERIMENT USES FIRE AND STEAM…GET ADULT HELP BEFORE YOU OPERATE THE ENGINE.

Here’s what you do:


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Food Dye Currents

Sunday September 5, 2010

When something feels hot to you, the molecules in that something are moving very fast. When something feels cool to you, the molecules in that object aren’t moving quite so fast. Believe it or not, your body perceives how fast molecules are moving by how hot or cold something feels. Your body has a variety of antennae to detect energy. Your eyes perceive certain frequencies of electromagnetic waves as light. Your ears perceive certain frequencies of longitudinal waves as sound. Your skin, mouth and tongue can perceive thermal energy as hot or cold. What a magnificent energy sensing instrument you are!


Let’s find out how to watch the hot and cold currents in water. Here’s what you need to do:


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Making Clouds

Sunday September 5, 2010

Indoor Rain Clouds

Making indoor rain clouds demonstrates the idea of temperature, the measure of how hot or cold something is. Here’s how to do it:


Take two clear glasses that fit snugly together when stacked. (Cylindrical glasses with straight sides work well.)


Fill one glass half-full with ice water and the other half-full with very hot water (definitely an adult job – and take care not to shatter the glass with the hot water!). Be sure to leave enough air space for the clouds to form in the hot glass.


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Peanut Energy

Sunday September 5, 2010

This experiment is for advanced students. Did you know that eating a single peanut will power your brain for 30 minutes? The energy in a peanut also produces a large amount of energy when burned in a flame, which can be used to boil water and measure energy.


Peanuts are part of the bean family, and actually grows underground (not from trees like almonds or walnuts).  In addition to your lunchtime sandwich, peanuts are also used in woman’s cosmetics, certain plastics, paint dyes, and also when making nitroglycerin.


What makes up a peanut?  Inside you’ll find a lot of fats (most of them unsaturated) and  antioxidants (as much as found in berries).  And more than half of all the peanuts Americans eat are produced in Alabama. We’re going to learn how to release the energy inside a peanut and how to measure it.


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Boiling Room Temperature Water

Sunday September 5, 2010

The triple point is where a molecule can be in all three states of matter at the exact same time, all in equilibrium. Imagine having a glass of liquid water happily together with both ice cubes and steam bubbles inside, forever! The ice would never melt, the liquid water would remain the same temperature, and the steam would bubble up. In order to do this, you have to get the pressure and temperature just right, and it’s different for every molecule.


The triple point of mercury happens at -38oF and 0.000000029 psi. For carbon dioxide, it’s 75psi and -70oF. So this isn’t something you can do with a modified bike pump and a refrigerator.


However, the triple point of water is 32oF and 0.089psi. The only place we’ve found this happening naturally (without any lab equipment) is on the surface of Mars.


Because of these numbers, we can get water to boil here on Earth while it stays at room temperature by changing the pressure using everyday materials. (If you have a vacuum pump, you can have the water boil at the freezing point of 32oF.)


Here’s what you need to do:


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Stairstep Candles

Sunday September 5, 2010

Fire is a chemical reaction (combustion) involving hot gases and plasma. The three things you need for a flame are oxygen, fuel, and a spark. When the fuel (gaseous wax) and oxygen (from the air) combine in a flame, one of the gases produced is carbon dioxide.


Most people think of carbon dioxide as dry ice, and are fascinated to watch the solid chunk sublimate from solid straight to gas, skipping the liquid state altogether. You’ve seen the curls of dry ice vapor curl down and cover the floor in a thick, wispy fog. Is carbon dioxide always more dense than air, or can we get it to float?


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Soaking Up Rays

Sunday September 5, 2010

Heat is transferred by radiation through electromagnetic waves. Remember, when we talked about waves and energy? Well, heat can be transferred by electromagnetic waves. Energy is vibrating particles that can move by waves over distances right? Well, if those vibrating particles hit something and cause those particles to vibrate (causing them to move faster/increasing their temperature) then heat is being transferred by waves. The type of electromagnetic waves that transfer heat are infra-red waves. The Sun transfers heat to the Earth through radiation.


If you hold your hand near (not touching) an incandescent light bulb until you can feel heat on your hand, you’ll be able to understand how light can travel like a wave. This type of heat transfer is called radiation.


Now don’t panic. This is not a bad kind of radiation like you get from x-rays. It’s infra-red radiation. Heat was transferred from the light bulb to your hand. The energy from the light bulb resonated the molecules in your hand. (Remember resonance?) Since the molecules in your hand are now moving faster, they have increased in temperature. Heat has been transferred! In fact, an incandescent light bulb gives off more energy in heat then it does in light. They are not very energy efficient.


Now, if it’s a hot sunny day outside, are you better off wearing a black or white shirt if you want to stay cool? This experiment will help you figure this out:


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Liquid Crystals

Sunday September 5, 2010

If you’ve completed the Soaking Up Rays experiment, you might still be a bit baffled as to why there’s a difference between black and white. Here’s a great way to actually “see” radiation by using liquid crystal thermal sheets.


You’ll need to find a liquid crystal sheet that has a temperature range near body temperature (so it changes color when you warm it with your hands.)


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Simple Microscope & Telescope

Wednesday September 1, 2010

Did you know you can create a compound microscope and a refractor telescope using the same materials? It’s all in how you use them to bend the light. These two experiments cover the fundamental basics of how two double-convex lenses can be used to make objects appear larger when right up close or farther away.


Things like lenses and mirrors can bend and bounce light to make interesting things, like compound microscopes and reflector telescopes. Telescopes magnify the appearance of some distant objects in the sky, including the moon and the planets. The number of stars that can be seen through telescopes is dramatically greater than can be seen by the unaided eye.


Materials


  • A window
  • Dollar bill
  • Penny
  • Two hand-held magnifying lenses
  • Ruler
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Microwhat?

Saturday July 31, 2010

Welcome to our unit on microscopes! We’re going to learn how to use our microscope to make things appear larger so we can study them more easily. Think about all the things that are too small to study just with your naked eyeballs: how many can you name?


Let’s start from the inside out – before you haul out your own microscope, we’re going to have a look at what it can do. I’ve already prepared a set of slides for you below.  Take out a sheet of paper and jot down your guesses – here’s how you do it:


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Anatomy of the Microscope

Saturday July 31, 2010

Nose? Objective? Stage? What kind of class is this?  Well, some of the names may sound a bit odd, but this video will show you what they are and how they are used. As you watch the video, touch the corresponding part of your microscope to get a feel for how it works.


NOTE: Be very careful NOT to raise the stage too high or you’ll crack the objective lens!  Always leave a space between the stage and the lens!! Anytime you use the coarse adjustment knob, always look at the stage itself, NOT through the eyepiece (for this very reason). When you use the fine adjustment knob, that’s when you look through the eyepiece.




More questions to ask:

1. After you’ve learned the different parts of the microscope, swing around and teach it to a nearby grown-up to test your knowledge. See if you can find all these parts: eyepiece, base (legs), objective lens, eyepiece, diaphragm (or iris), stage, fine and coarse adjustment knobs, mirror/lamp, nose.


2. Show your grown-up which parts never to touch with your fingers.


3. What’s the proper way to use the coarse adjustment knob so you don’t crack the objective lens?


Care and Cleaning

1. Pick up the microscope with two hands. Always grab the arm with one hand and the legs (base) with the other.


2. Don’t touch the lenses with your fingers. The oil on your fingers will smudge and etch the lenses. Use an optical wipe if you must clean the lenses. Steer clear of toilet paper and paper towels – they will scratch your lenses.


3. When you’re done with your scope for the day, reset it so that it’s on the lowest power of magnification and lower the stage to the lowest position. Cover it with your dust cover or place it in its case.


Preparing a Dry Mount Slide

Saturday July 31, 2010

Make sure you’ve completed the How to Use a Microscope activity before you start here!


This is simplest form of slide preparation!  All  you need to do is place it on the slide, use a coverslip (and you don’t even have to do that if it’s too bumpy), and take a look through the eyepiece.  No water, stains, or glue required.


You know that this is the mount type you need when your specimen doesn’t require water to live. Good examples of things you can try are cloth fibers (the image here is of cotton thread at 40X magnification), wool, human hair, salt, and sugar. It’s especially fun to mix up salt and sugar first, and then look at it under the scope to see if you can tell the difference.


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Preparing a Wet Mount Slide

Saturday July 31, 2010

Make sure you’ve completed the How to Use a Microscope activity before you start here!


Anytime you have a specimen that needs water to live, you’ll need to prepare a wet mount slide. This is especially useful for looking at pond water (or scum), plants, protists (single-cell animals), mold, etc. When you keep your specimen alive in their environment, you not only get to observe it, but also how it eats, lives, breathes, and interacts in its environment.


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Slide Preparation: Staining

Saturday July 31, 2010

Make sure you’ve completed the How to Use a Microscope and also the Wet Mount activities before you start here!


If your critter is hard to see, you can use a dye to bring out the cell structure and make it easier to view.  There are lots of different types of stains, depending on what you’re looking at.


The procedure is simple, although kids will probably stain not only their specimens, but the table and their fingers, too.  Protect your surfaces with a plastic tablecloth and use gloves if you want to.


We’re going to use an iodine stain, which is used in chemistry as an indicator (it turns dark blue) for starch. This makes iodine a good choice when looking at plants. You can also use Lugol’s Stain, which also reacts with starch and will turn your specimen black to make the cell nuclei visible. Methylene blue is a good choice for looking at animal cells, blood, and tissues.


In addition to your specimen, you’ll need to get out your slides, microscope, cover slips, eye dropper, tweezers, iodine (you can use regular, non-clear iodine from the drug store), and a scrap of onion. If you can find an elodea leaf, add it to your pile (check with your local garden store). Here’s what you do:


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Slide Preparation: Heat Fixes

Saturday July 31, 2010

Make sure you’ve completed the How to Use a Microscope and also the Wet Mount and Staining activities before you start here!


If you tried looking at animal cells already, you know that they wiggle and squirm all over the place. And if you tried looking when using the staining technique, you know it only makes things worse.


The heat fix technique is the one you want to use to nail your specimen to the slide and also stain it to bring out the cell structure and nuclei. This is the way scientists can look at things like bacteria.


You’re going to need your microscope, slides, cover slips, eyedropper, toothpicks or tweezers, candle and matches (with adult help), stain (you can use regular iodine or Lugol’s Stain), sugar, yeast, and a container to mix your specimen in. Here’s what you do:


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PVA Slime

Wednesday June 30, 2010

Instead of using glue as a polymer (as in the slime recipes above), we're going to use PVA (polyvinyl alcohol). Most liquids are unconnected molecules bouncing around. Monomers (single molecules) flow very easily and don't clump together. When you link up monomers into longer segments, you form polymers (long chains of molecules).

Polymers don't flow very easily at all - they tend to get tangled up until you add the cross-linking agent, which buddies up the different segments of the molecule chains together into a climbing-rope design.

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Bouncy Putty Slime

Wednesday June 30, 2010

The glue is a polymer, which is a long chain of molecules all hooked together like tangled noodles. When you mix the two solutions together, the water molecules start linking up the noodles together all along the length of each noodle to get more like a fishnet. Scientists call this a polymetric compound of sodium tetraborate and lactated glue. We call it bouncy putty.


Here’s what you do:


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Football Ice Cream

Wednesday June 30, 2010

Is it hot where you live in the summer? What if I gave you a recipe for making ice cream that doesn’t require an expensive ice cream maker, hours of churning, and can be made to any flavor you can dream up? (Even dairy-free if needed?)


If you’ve got a backyard full of busy kids that seem to constantly be in motion, then this is the project for you.  The best part is, you don’t have to do any of the churning work… the kids will handle it all for you!


This experiment is simple to set up (it only requires a trip to the grocery store), quick to implement, and all you need to do guard the back door armed with a hose to douse the kids before they tramp back into the house afterward.


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Colored Campfires and Rainbows

Wednesday June 30, 2010

Always have a FIRE EXTINGUISHER and ADULT HELP handy when performing fire experiments. NO EXCEPTIONS.

This video will show you how to transform the color of your flames. For a campfire, simply sprinkle the solids into your flames (make sure they are ground into a fine powder first) and you’ll see a color change. DO NOT do this experiment inside your house – the fumes given off by the chemicals are not something you want in your home!


One of the tricks to fire safety is to limit your fuel. The three elements you need for a flame are: oxygen, spark, and fuel.  To extinguish your flames, you’ll have to either wait for the fuel to run out or smother the flames to cut off the oxygen. When you limit your fuel, you add an extra level of safety to your activities and a higher rate of success to your eyebrows.


Here’s what we’re going to do: first, make your spectrometer: you can make the simple spectrometer or the more-advanced calibrated spectrometer. Next, get your chemicals together and build your campfire. Finally, use your spectrometer to view your flames.


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Sewer Slime

Wednesday June 30, 2010

Guar gum comes from the guar plant (also called the guaran plan), and people have found a lot of different and interesting uses for it.  It’s one of the primary substitutes for fat in low-fat and fat-free foods. Cooks like to  use guar gum in foods as it has 8 times the thickening power of cornstarch, so much less is needed for the recipe. Ice cream makers use it to keep ice crystals from forming inside the carton. Doctors use it as a laxative for their patients.


When we teach kids how to make slime using guar gum, they call it “fake fat” slime, mostly because it’s used in fat-free baking.  You can find guar gum in health food stores or order it online. We’re going to whip up a batch of slime using this “fake fat”. Ready?


Here’s what you do:
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Volcanoes

Wednesday June 30, 2010

If you’ve ever wanted to make your own version of a volcano that burps and spit all over the place, then this is the experiment for you.  We used to teach kids how to make genuine Fire & Flame volcanoes, but parents weren’t too happy about the shower of sparks that hit the ceiling and fireballs that shot out of the thing… so we’ve toned it down a bit to focus more on the lava flow.


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Water Purification

Wednesday June 30, 2010

Ever wonder how the water draining down your sink gets clean again? Think about it: The water you use to clean your dishes is the same water that runs through the toilet.  There is only one water pipe to the house, and that source provides water for the dishwasher, tub, sink, washing machine, toilet, fish tank, and water filter on the front of your fridge.  And there’s only one drain from your house, too!  How can you be sure what’s in the water you’re using?


This experiment will help you turn not only your coffee back into clear water, but the swamp muck from the back yard as well.  Let’s get started.
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Calibrated Spectrometer

Wednesday June 30, 2010

Ever play with a prism? When sunlight strikes the prism, it gets split into a rainbow of colors. Prisms un-mix the light into its different wavelengths (which you see as different colors). Diffraction gratings are tiny prisms stacked together.

When light passes through a diffraction grating, it splits (diffracts) the light into several beams traveling at different directions. If you’ve ever seen the ‘iridescence’ of a soap bubble, an insect shell, or on a pearl, you’ve seen nature’s diffraction gratings.

Scientist use these things to split incoming light so they can figure out what fuels a distant star is burning. When hydrogen burns, it gives off light, but not in all the colors of the rainbow, only very specific colors in red and blue. It’s like hydrogen’s own personal fingerprint, or light signature.

While this spectrometer isn't powerful enough to split starlight, it's perfect for using with the lights in your house, and even with an outdoor campfire.  Next time you're out on the town after dark, bring this with you to peek different types of lights - you'll be amazed how different they really are. You can use this spectrometer with your Colored Campfire Experiment also.

SPECIAL NOTE: This instrument is NOT for looking at the sun. Do NOT look directly at the sun. But you can point the tube at a sheet of paper that has the the sun’s reflected light on it.

Here's what you do:

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Pinhole Solar Projector

Wednesday June 30, 2010

You might be curious about how to observe the sun safely without losing your eyeballs. There are many different ways to observe the sun without damaging your eyesight. In fact, the quickest and simplest way to do this is to build a super-easy pinhole camera that projects an image of the sun onto an index card for you to view.


CAUTION: DO NOT LOOK AT THE SUN THROUGH ANYTHING WITH LENSES!!


This simple activity requires only these materials:


  • tack
  • 2 index cards (any size)
  • sunlight
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Streaming Water

Tuesday June 1, 2010

Fill the bathtub and climb in. Grab your water bottle and tack and poke several holes into the lower half the water bottle. Fill the bottle with water and cap it. Lift the bottle above the water level in the tub and untwist the cap. Water should come streaming out. Close the cap and the water streams should stop. Open the cap and when the water streams out again, can you “pinch” two streams together using your fingers?


Materials: A tack, and a plastic water bottle with cap, and bathtub


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Sneaky Bottles

Tuesday June 1, 2010

This experiment illustrates that air really does take up space! You can’t inflate the balloon inside the bottle without the holes, because it’s already full of air. When you blow into the bottle with the holes, air is allowed to leak out making room for the balloon to inflate. With the intact bottle, you run into trouble because there’s nowhere for the air already inside the bottle to go when you attempt to inflate the balloon.


You’ll need to get two balloons, one tack, and two empty water bottles.


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Squished Balloon

Tuesday June 1, 2010

Fire eats air, or in more scientific terms, the air gets used up by the flame and lowers the air pressure inside the jar. The surrounding air outside the jar is now at a higher pressure than the air inside the jar and it pushes the balloon into the jar. Remember: Higher pressure pushes!


Materials: a balloon, one empty glass jar, scrap of paper towel , matches with an adult


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Fountain Bottle

Tuesday June 1, 2010

As you blow air into the bottle, the air pressure increases inside the bottle. This higher pressure pushes on the water, which gets forced up and out the straw (and up your nose!).


Materials: small lump of clay, water, a straw, and one empty 2-liter soda bottle.


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Bubble Experiments

Monday May 31, 2010
Magician Tom Noddy

If you’re fascinated by the simple complexity of the standard soap bubble, then this is the lab for you. You can easily transform these ideas into a block-party Bubble Festival, or just have extra fun in the nightly bathtub. Either way, your kids will not only learn about the science of water, molecules, and surface tension, they’ll also leave this lab cleaner than they started (which is highly unusually for science experiments!)


Soap also makes water stretchy. If you’ve ever tried making bubbles with your mouth just using spit, you know that you can’t get the larger, fist-sized spit bubbles to form completely and detach to float away in the air. Spit is 94% water, and water by itself has too much surface tension, too many forces holding the molecules together. When you add soap to it, they relax a bit and stretch out. Soap makes water stretch and form into a bubble.
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Ping Pong Funnel

Monday May 31, 2010

As you blow into the funnel, the air under the ball moves faster than the other air surrounding the ball, which generates an area of lower air pressure. The pressure under the ball is therefore lower than the surrounding air which is, by comparison, at a higher pressure. This higher pressure pushes the ball back into the funnel, no matter how hard you blow or which way you hold the funnel. The harder you blow, the more stuck the ball becomes. Cool.


Materials: A funnel and a ping pong ball


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Magic Water Glass Trick

Monday May 31, 2010

Where’s the pressure difference in this trick?


At the opening of the glass. The water inside the glass weighs a pound at best, and, depending on the size of the opening of the glass, the air pressure is exerting 15-30 pounds upward on the bottom of the card. Guess who wins? Tip, when you get good at this experiment, try doing it over a friend’s head!


Materials: a glass, and an index card large enough to completely cover the mouth of the glass.


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Hot Air Balloon

Monday May 31, 2010

About 400 years ago, Leonardo da Vinci wanted to fly… so he studied the only flying things around at that time: birds and insects. Then he did what any normal kid would do—he drew pictures of flying machines!


Centuries later, a toy company found his drawing for an ornithopter, a machine that flew by flapping its wings (unlike an airplane, which has non-moving wings). The problem (and secret to the toy’s popularity) was that with its wing-flapping design, the ornithopter could not be steered and was unpredictable: It zoomed, dipped, rolled, and looped through the sky. Sick bags, anyone?


Hot air balloons that took people into the air first lifted off the ground in the 1780s, shortly after Leonardo da Vinci’s plans for the ornithopter took flight. While limited seating and steering were still major problems to overcome, let’s get a feeling for what our scientific forefathers experienced as we make a balloon that can soar high into the morning sky.


Materials: A lightweight plastic garbage bag, duct or masking tape, a hand-held hair dryer. And a COLD morning.


Here’s what you do:


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Diaper Wind Bag

Monday May 31, 2010

Lots of science toy companies will sell you this experiment, but why not make your own? You’ll need to find a loooooong bag, which is why we recommend a diaper genie. A diaper genie is a 25′ long plastic bag, only both ends are open so it’s more like a tube. You can get three 8-foot bags out of one pack.


Kids have a tendency to shove the bag right up to their face and blow, cutting off the air flow from the surrounding air into the bag. When they figure out this experiment and perform it correctly, this is one of those oooh-ahhh experiments that will leave your kids with eyes as big as dinner plates.


Here’s what you do:


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Genie in a Bottle

Monday May 31, 2010

While this isn’t actually an air-pressure experiment but more of an activity in density, really, it’s still a great visual demonstration of why Hot Air Balloons rise on cold mornings.


Imagine a glass of hot water and a glass of cold water sitting on a table, side by side. Now imagine you have a way to count the number of water molecules in each glass. Which glass has more water molecules?


The glass of cold water has way more molecules… but why? The cold water is more dense than the hot water. Warmer stuff tends to rise because it’s less dense than colder stuff and that’s why the hot air balloon in experiment 1.10 floated up to the sky.


Clouds form as warm air carrying moisture rises within cooler air. As the warm, wet air rises, it cools and begins to condense, releasing energy that keeps the air warmer than its surroundings. Therefore, it continues to rise. Sometimes, in places like Florida, this process continues long enough for thunderclouds to form. Let’s do an experiment to better visualize this idea.


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Soda Can Trick

Monday May 31, 2010

When air moves, the air pressure decreases. This creates a lower air pressure pocket right between the cans relative to the surrounding air. Because higher pressure pushes, the cans clink together. Just remember – whenever there’s a difference in pressure, the higher pressure pushes.


You will need about 25 straws and two empty soda cans or other lightweight containers


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Going Further with Advanced Chemistry

Monday May 31, 2010

This experiment is for advanced students.


One of my best teaching tools for science developed from a brain freeze one afternoon in class. I went to the board to draw the chlorophyll wheel and drew a complete blank.


“Let’s say I forgot how to draw the wheel.” I turned to the class, marker in hand, and scanned the room. Puzzled faces, the blank faces I expected, but, what was that? A few smiles scattered about the room.


As I pulled out and some volunteered info, we got into that wheel. They also found that it was easier to know what to do next than to have me tell them to find it in their book and be prepared…I was coming back to them. Students frantically finding the wheel in their biology books so they were armed when I came to them.


It was a great experience, and my lectures were a lot more fun and interactive from then on.


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Air Takes Space

Monday May 31, 2010

You’re about to play with one of the first methods of underwater breathing developed for scuba divers hundreds of years ago.! Back then, scientists would invert a very large clear, bell-shaped jar over a diver standing on a platform, then lower the whole thing into the water. Everyone thought this was a great idea, until the diver ran out of breathable air…


Materials: 12″ flexible tubing, two clear plastic cups, bathtub


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Solar Cookies

Saturday May 1, 2010

Can you use the power of the sun without using solar cells? You bet! We’re going to focus the incoming light down into a heat-absorbing box that will actually cook your food for you.


Remember from Unit 9 how we learned about photons (packets of light)?  Sunlight at the Earth’s surface is mostly in the visible and near-infrared (IR) part of the spectrum, with a small part in the near-ultraviolet (UV). The UV light has more energy than the IR, although it’s the IR that you feel as heat.


We’re going to use both to bake cookies in our homemade solar oven. There are two different designs – one uses a pizza box and the other is more like a light funnel. Which one works best for you?


  • Two large sheets of poster board (black is best)
  • Aluminum foil
  • Plastic wrap
  • Black construction paper
  • Cardboard box
  • Pizza box (clean!)
  • Tape & scissors
  • Reusable plastic baggies
  • Cookie dough (your favorite)
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Solar Boat

Saturday May 1, 2010

expansionpacks_clip_image004_0000Does it really matter what angle the solar cell makes with the incoming sunlight? If so, does it matter much? When the sun moves across the sky, solar cells on a house receive different amounts of sunlight. You’re going to find out exactly how much this varies by building your own solar boat.


We’re going to use solar cells and the basic ideas from Unit 10 (Electricity & Robotics) to build a solar-powered race car.  You’ll need to find these items below.  Note – if you have trouble locating parts, check the shopping list for information on how to order it straight from us.


  • Solar motor
  • Solar cell
  • Foam block (about 6” long)
  • Alligator clip leads
  • Propeller (you can rip one off an old small personal fan or old toy, or find them at hobby stores)

Here’s what you do:


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