How can water exist as a solid and a liquid at 0 degrees Celsius?

Answer 1

When liquid, individual water particles cling together in a way that allows them to move around, as long as they stick together. Imagine a bunch of people all holding hands, running around outside. That's sort of how the molecules move.

When water freezes at about 0 degrees Celsius, the individual water particles cling together in a different way. They can no longer move, but they settle into a pattern that makes the water more solid and makes it harder for the molecules to separate. Imagine the group of people holding hands again. Now imagine they all lie down in a circle, still holding hands. They can't run around anymore, but it is now harder to separate them.

I hope that answers your question.

Answer 2

Ice does not melt all at once, and water does not freeze all at once. If you add heat energy to ice, it will melt at 0 oC. If you take away heat energy, water will freeze at 0 oC. The temperature will not change until the phase change is complete, so during the phase change, both liquid water and ice will be present.

Answer 3

This temperature (0o Celsius) is the freezing temperature of water; this is when it freezes into what we refer to as icewhich is its most compact state, where the molecules cannot compress together anymore.

Answer 4

The atoms slow down there movement becoming more compact till the water turns to ice.