1-2 Phase Change, Slide 3

To change something from a solid to a liquid, or from a liquid to a gas (like water to ice, or water to steam), it needs energy. This energy helps the tiny parts that make up the thing move apart from each other.

•When something is changing from one form to another, like ice melting to water, we can add or take away energy, but it won’t get hotter or colder until it has completely changed.