As the so-called British “summer” demonstrated, water is all around us. It’s a molecule few of us think twice about, it’s that mundane and every day. It’s just O and two H’s, right?
But water, for such a simple compound, has several interesting and ultimately massively influential properties. For example, you can’t squash it. If you could, there’d be no waves in the sea nor would puddles splash. The reason is fluids don’t compress well, as Jim H explains:
“Atoms or molecules in a gas are not bound to others and are widely separated and thus can be compressed. In water, the molecules are close together and the electric fields of the electrons make it difficult to compress… Water can be compressed, but not much and not easily. Given enough pressure, however, any matter can and will compress.” More>
Another unusual property of water is that for every given molecule when it gets colder it gets larger. This is odd as heat is vibration and usually as molecules get colder they vibrate less, so are able to get closer. Yet when water freezes is turns into (solid) ice, which is less dense that (liquid) water. Mr Jeffy321 explains why…
“The reason why water expands upon freezing is due to the intermolecular forces of attraction which exist between the water molecules, in particular, hydrogen bonding. As water freezes, the molecules begin to slow down.”
“As the molecules slow down they become less and less able to break free of these attractive forces and begin to align themselves in a position which takes the least energy. Due to the geometry of the water molecule, this least energy position forms a lattice that just happens to be larger than if the molecules were in the liquid state.” More>
So this explains why ice cubes float in your drink: they’re less dense than the water they’re sitting in. Another “phenomenon” water is associated with is the Coriolis effect, where water in different hemispheres goes down a sink in opposite directions (clockwise or anti-) in different hemispheres. The thing is, turns out it’s an urban myth. Nemesis explains:
“It has always been popular myth that water flows down the plug-hole in an opposite direction to what it would do if located in the opposite hemisphere. This myth even made it into the Simpsons (Bart vs Australia).
The truth is that the direction of flow is more likely to be influenced by more immediate factors e.g. the shape of the basin.” More>
So there you have it: it gets bigger when it gets cold, it causes puddles to splash and confuses Bart and Homer. And there’s yet more. For protecting fish from lightning and the meaning of life, see our links below…
– Yahoo! UK & Ireland Answers
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