Subscribe

7th grade · Science · Unit 10 of 12

Particles and Heat

How heating and cooling change matter

What your child practices

Solids, liquids and gases in the particle model, faster particles when heated and slower when cooled, melting, freezing, evaporation and condensation, and why mass stays the same in a phase change.

California Content Standards learning standard: MS-PS1-4 · how adding or removing thermal energy changes particle motion, temperature and state

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    In a liquid, the particles…

    • are locked in place
    • are close but can slide past each other
    • are far apart

  2. Question 2

    What is evaporation?

    • A solid changing to a liquid
    • A gas changing to a liquid
    • A liquid changing to a gas

  3. Question 3

    What happens to the particles of a substance when it is heated?

    • They stop moving
    • They move faster
    • They disappear

  4. Question 4

    Butter left on a warm counter gets soft and runny. What is happening?

    • The particles are disappearing
    • The butter is freezing
    • Heated particles move faster, so the solid is starting to melt

  5. Question 5

    What is freezing?

    • A gas changing to a liquid
    • A solid changing to a liquid
    • A liquid changing to a solid

  6. Question 6

    A sealed bag holds 50 g of ice. The ice melts. What will the bag hold?

    • less than 50 g of water
    • 50 g of water
    • more than 50 g of water

More 7th grade