Ice is less dense than liquid water because it forms a Hexagonal crystal structure which is an 'open' structure. In solid ice each water molecule is hydrogen bonded to 4 other water molecules and in liquid water each of the water molecules is hydrogen bonded on average to about 3.5 other water molecules. So in ice the the molecules are held slightly farther apart making the ice less dense.
Water, steam and ice are all made of H2O. In steam or water vapor the molecules are not bonded, each water molecule is free to move around in the air. In water the H2O molecules break and reform bonds. That is why the water is a liquid, the breaking and reforming of bonds allow it to flow. On average there are about 3.5 hydrogen bonds for each molecule. In ice the bonds do not break, a rigid crystal lattice is formed with each H2O molecule bonded to 4 other H2O molecules.
I fail to understand why you think the density of water has anything to do with CO2 in the atmosphere. Please explain the linkage.
Yes there is a big jump in the amount of energy released when water turns to ice compared to changing the temperature of water.
Gravity for fucks sake.
That says nothing.
You don't mention gravity?
What has gravity got to do with it? Gravity doesn't pull CO2 down out of the atmosphere. Gravity doesn't pull H2O down out of the atmosphere. What has gravity got to do with it?
If you're going to ask questions, you have to learn to understand your own questions.
If a gas is lighter than air, gravity doesn't cause it to end up on the ground. The heavier column of air is between the two.
This is mostly an assumption but hydrogen should be able to expand more than either carbon or oxygen.
Ballocks.
Agreed!
Elements that expand on freezing are silicon, gallium, germanium, antimony, bismuth and plutonium.
No. The expansion of water is an emergent property, not inherent in O or H.
I know. That's why I italicized elements, because I didn't have the exact answer to the question you asked.