Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

Solids, liquids and gases change state when they are heated or cooled. Processes such as evaporation and boiling change the state of substances. A particle model can be used to show how solids, ...

The distances between particles are smallest in the solid, they are larger in the liquid and larger again in the gas. The particles in gases and liquids move more freely than in solids, so their ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Hi, I'm Diana. Great to be with you today. Have you ever seen one of these? It's a hot air balloon.

Imagine a liquid that flows freely one moment, then stiffens into a near-solid the next, and then can switch back with a simple change in temperature. Researchers at the University of Chicago Pritzker ...

To melt a solid, heat it. To freeze a liquid, cool it. It's simple—except when it isn't, because quantum mechanics can flip even the intuitive logic of melting and freezing on its head. Physicists ...