Describe and represent how particles are arranged and move differently in solids, liquids, and gases.
Solids, liquids, and gases all look and act differently, and the reason comes down to how their particles are arranged and how fast they move. In a solid, particles are packed close together in a fixed pattern and mostly just vibrate in place, which is why a solid holds its shape. In a liquid, particles are still close but can slide past each other, so a liquid flows and takes the shape of its container.
In a gas, particles are spread far apart and move quickly in every direction, bouncing off whatever they hit. That is why a gas spreads out to fill an entire room instead of staying in one spot. The same substance, like water, can move through all three particle arrangements: ice, liquid water, and water vapor are the same particles, just arranged and moving differently.
Mastery looks like: They can describe and sketch how particle arrangement and motion differ across solid, liquid, and gas, using water as the example.
Common stumbles: Thinking the particles themselves change into different particles between states, rather than just rearranging; mixing up which state has the fastest-moving particles.