Observe changes of state in a particle model

Make a prediction and investigate

Observe the initial particle arrangement. Change the temperature control gradually and record the arrangement and movement at two conditions.

Controls in the actual lab

• Temperature: starts at 20 °C; available range -10–120 °C.

Heat a solid and it can melt. Heat a liquid and it can boil. Cool them and they go back. Same particles, different spacing.

Discuss the evidence

Separate what the particles do from the label used for the state. Use both observations in your explanation.

Try it beyond the activity

Explain one way a particle picture helps understanding and one detail of real matter it leaves out.

Record your thinking

Sources and limits

This companion uses the published States activity and its learning guidance. Review any original sources linked there. It is a discussion plan by Lesson Worlds, not a scored assessment, a standards certification, or evidence of learning gains.

Use this activity with a learner

Families and educators · choose by prior knowledge

Learning goal: Heat a solid and it can melt. Heat a liquid and it can boil. Cool them and they go back. Same particles, different spacing.

Before you begin: Read the controls for Temperature. Make one prediction before changing a setting.

Check understanding: Ask for one observation, the evidence that supports it, and a question to investigate next.

A simulation simplifies the real world. Explain which conditions stayed fixed; a successful run alone does not demonstrate mastery.

Activity and guide by Lesson Worlds. About the platform.