Heating and Cooling Change Matter

Science · Matter & Materials · ages 7-9

Name ______________________ Date ____________

What is it called when a liquid turns into a solid?
- Melting
- Freezing
- Boiling
What is it called when a solid turns into a liquid?
- Melting
- Freezing
- Boiling
Water freezes at 0°C.
Circle one: True False
What happens to the particles in a solid as you heat it until it melts?
- They move slower and pack closer
- They stop moving completely
- They move faster and spread apart
Mia heats a pot of water on the stove. At what temperature, in °C, will it start to boil?
Answer: ______________
A puddle of water is left outside on a freezing winter night. What will most likely happen to it?
- It will freeze into ice
- It will boil into steam
- It will stay exactly the same
Which of these is the same kind of change as ice melting into water?
- A block of wood breaking in half
- A balloon popping
- Butter melting on hot toast
Ali says, 'Ice melts because the freezer makes it colder.' What is wrong with what Ali said?
- Ice never melts, it only shrinks
- Melting happens because the ice gets warmer, not colder
- Melting only happens at 100°C

Answer key

For grown-ups. Fold this page away before handing over the rest.

Freezing · When a liquid gets cold enough, it turns into a solid. That change is called freezing.
Melting · When a solid gets warm enough, it turns into a liquid. That change is called melting.
True · 0°C is the exact temperature where liquid water turns to ice, and ice turns to water.
They move faster and spread apart · Heat adds energy to particles, so they move faster and spread further apart until the solid becomes a liquid.
100 · 100°C is the exact temperature where liquid water turns to steam.
It will freeze into ice · Freezing temperatures cool the water down to 0°C or below, so the puddle turns into ice.
Butter melting on hot toast · Butter melting is a solid turning into a liquid because of heat, just like ice melting into water.
Melting happens because the ice gets warmer, not colder · Melting happens when something gets warmer, not colder. The extra heat makes the ice's particles move fast enough to become liquid.