Science 4th grade | UNIT 3: Solids‚ liquids and gases 3.4 Melting‚ Freezing‚ and boiling
Sabera's ice-cream started as a frozen solid. When the sun heated the ice-cream it changed to a liquid. This change from solid to liquid is called melting. We can show melting in this way:
solid 
liquid
Freezing is the opposite of melting. Freezing is when something changes from a liquid to a solid.
Activity 3.4a (What happens to ice when it is heated?)
You will need: ice cubes - pot (pan or saucepan) hot plate
Put the ice cubes into the pot.
Heat the pot on the hot plate.
Predict what you think will happen to the ice.
What does happen to the ice?
This is the phase change the ice goes through when you heat it:
solide phase (ice) 
liquid phase (water)
Now heat the water until it starts to boil. Observe how the water changes.
Safety: Be careful of the hot plate, it can burn you. Steam can also burn you.
Activity 3.4b (What happens to steam when it is cooled?)
You will need: steam from boiling water a board with a shiny surface a plastic container - a freezer
Your teacher will hold the shiny board in the steam.
Predict what you think will happen to the steam. Observe what happens.
Safety: Be careful of the steam, it can burn you.
Put the liquid you collect in the freezer for 30 min. Predict what will happen to it.
Questions
1) Copy and complete the sentence below. Fill in the phase changes the water went through when it cooled down.
steam (_____ phase 
_____ (_____ phase)
2) What happens to the water when you put it in the freezer?
3) Copy and complete the sentence below. Fill in the phase changes the water went through when it froze.
water (_____ phase _____ (_____ phase)