Now, that you’ve spent some quality time with atoms and that wacky electron fellow you have a bit of an understanding of what is inside everything. The next thing you need to know is…what’s everything?
Now, that you’ve spent some quality time with atoms and that wacky electron fellow you have a bit of an understanding of what is inside everything. The next thing you need to know is…what’s everything?
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You’re right – most molecules are packed more tightly in their solid form. However, the crystal structure of ice is a hexagon with a hole in the middle, which is why ice is one of the very few molecules that expands when it goes from a liquid to a solid. Most molecules get smaller and more tightly packed when they go from liquid to solid. Click here for a look at the crystal structure. Note the hexagon-honeycomb shape…which is also why snowflakes have six points.
Could you explain the why’s behind solid water being less dense than liquid water? One would think that the molecules would be packed most tightly in ice and less tightly in water. What’s going on?
Sure – you can have liquids heavier than solids, and gases heavier than liquids. It depends on the temperature and pressure of the substances. Ice floats, right? So solid water ice is ‘lighter’ than liquid water. A more scientific way to say it is that ice is less dense than liquid water. Note that the ice has to be ata certain temperature or this doesn’t work (the ice would melt and mix in with the liquid water).
If you had a column of Mercury, Copper, and Xenon, you could have a small chunk of solid copper near the top, the gaseous xenon in the middle (depending on how much you cram in there), and the liquid mercury at the bottom. It all depends on the atomic weights of things (mercury is a heavier element than xenon and copper) and how much of each one you have (this relates to the temperature and pressure). Does that help?
ok i understand but can any type of gas be heavier than a liquid? or a liquid heavier than a solid?
Ummm…. this is a tricky question. Each molecule has a different atomic weight, but depending on the pressure and temperature, you can get it to go from solid to liquid to gas, packing in more of less of the molecules with each state of matter. For example, solids have more molecules packed together than gases, so the thing you’re changing is the density (the amount of stuff you can cram into the same volume space). For example, a cup of solid carbon dioxide would weigh more than a cup of gaseous carbon dioxide, as there’s more CO2 molecules in the block of CO2 ice. Note – water is one of the very few molecules which expands when freezing, which is why ice floats (not sinks) in water…the ‘heaviest’ cup of water you’ll measure is at 4 degrees (F), meaning that water is the most dense at 4 deg F which is the temperature at the bottom of most large masses of pure water.
For most cases, fire is a mixture of gases that are chemically reaction together exothermically (giving off energy in the form of heat and light). If the flame is hot enough, you’ll also get plasma in there as well as the molecules ionize (as the electrons jiggle free and zip around on their own).
oh i forgot this other question: is there a gas that is heavier than water?
what kind of matter is fire?