Video narration
What changes inside an ice cube as it melts-and then as its water becomes gas? Particles are tiny pieces that make up water. In the ice cube, they are close together and vibrate in fixed positions. As the drink warms, heating gives them energy. They move faster. Here's the turn: the particles do not become bigger or turn into different particles. During melting, they leave fixed positions and slide past one another as liquid. Heat the water more, like in a kettle, and some particles move fast enough to escape. This is evaporation: particles escaping at the liquid's surface. When water boils, particles escape throughout liquid too. Far apart, they are a gas. So, in the ice cube and kettle, particles moved faster: they slid past one another as liquid, then some escaped far apart as gas.