I’ve always been curious but I can’t find much on it that isn’t just “HEE HOO ICE SOLID”
In: Chemistry
Ice is the same kind of solid as rocks are. In fact, technically speaking, ice is a mineral. On other planets with colder conditions, ice is a major part of their rock. It goes through the same processes (erosion, sedimentation, even plate tectonics) that rocks on Earth do, and can even “erupt” from ice-volcanoes.
But the question, based on your other comments, is “why *isn’t* water solid under normal Earth conditions”. Put another way, why is water’s melting point (0C/32F) relatively low compared to that of rock (usually ~1000 C or more)?
The full details are fairly complex, but there are a few major factors that determine a molecule’s melting point. The most important are how *heavy* the molecule is and how *strongly* it’s attracted to other molecules of the same kind. The heavier the molecule and the stronger the inter-molecular forces, the more likely it is to be solid at a given temperature.
Water happens to be a very light molecule. So light, in fact, that the fact that it’s not solid is actually less surprising than the fact that it’s not a *gas*. Similarly light molecules, like carbon dioxide (which is actually quite a bit heavier) are gases on Earth. The reason water isn’t a gas is the second factor: water molecules are very strongly attracted to one another, which lets them hold together as a liquid rather than break off individually as a gas.
Most rocks contain metals, which are usually heavy atoms. Earth rocks usually contain silicon, magnesium, or iron, all of which are much heavier than the oxygen and hydrogen in water, and usually contain much larger molecules with ten or twenty atoms. This means their molecules are much heavier, and therefore their boiling and melting points are much higher.
Latest Answers