What is Frozen water?

Water is usually a squishy, flowing liquid that you drink and splash in, but when it gets cold enough, its particles slow down and lock together to form hard frozen water, which we call ice.

Imagine your body after a long day of running around. When you are energetic, you wiggle and jump everywhere, just like water molecules floating in a pool. But if you get tired and sleepy, you curl up on the couch and stop moving much. Frozen water is exactly that: water molecules that have gotten "tired" from the cold and locked arms with their neighbors to stay still.

In a glass of juice, the liquid particles slide past each other easily, which is why you can pour it. In ice, they are stuck in place. This makes ice solid. You can hold an ice cube without it dripping through your fingers like water does. It feels cold and hard because those locked molecules have no room to wiggle away when you touch them.

Think about putting liquid water into a plastic ice cube tray in the freezer. As it freezes, the water expands slightly, pushing up against the sides of the tray. This is why ice floats on top of your drink! Because its molecules are spread out and locked tight, ice is lighter than the same amount of liquid water. So when you sip your lemonade, the ice cubes bob around on top instead of sinking to the bottom. It is just water wearing a stiff, crunchy jacket.