Solid, Liquid, Gas

Why it matters

Ice cubes clink in a glass, water flows freely, and steam vanishes into the air. The substance is identical, yet its behavior changes completely.

Predict first

What happens to the water particles when ice melts into liquid water?

Melting adds energy. Particles vibrate faster, break their fixed positions, and flow.

• The particles break into smaller pieces
• The particles gain energy and slide past each other — correct
• The particles disappear into the empty space
• The particles stop moving completely

What you do

Drag the temperature slider. Watch how particle spacing and motion change from solid to gas.

Check yourself

Which state has particles that are tightly packed in a regular pattern?

Solids have strong forces holding particles in fixed, ordered positions.

Why does a gas fill the entire container?

High kinetic energy and large intermolecular spaces allow gases to expand and diffuse.

During boiling, what happens to the temperature of the water?

Energy input breaks intermolecular forces rather than increasing kinetic energy (temperature).

• Solid — correct
• Liquid
• Gas
• Particles are far apart and move rapidly in all directions — correct
• Particles stick to the walls
• The container pushes the particles out
• Gas particles are larger than solid particles
• It rises continuously
• It stays constant until all liquid becomes gas — correct
• It drops suddenly