Ice & States of Matter

Science · Polar Regions · ages 7-9

Name ______________________ Date ____________

What are the three states water can be in?
- Hot, cold, warm
- Solid, liquid, gas
- Ice, snow, frost
Which kind of ice comes from frozen ocean water?
- Sea ice
- Glacier ice
- Snowball ice
Icebergs break off from glaciers.
Circle one: True False
Pip drops an ice cube into a glass of water. Using what you know about ice and water, what does the ice cube do?
- It floats, same size weighs less
- It sinks, because ice is a solid
- It stays floating in the middle of the water
Nora finds two chunks of ice at the polar museum. One is thin and salty. The other is thick and made of fresh water. Which chunk came from a glacier?
- The thin, salty chunk
- Both chunks came from a glacier
- The thick, fresh-water chunk
Why does the salty ocean need to get colder than fresh water before it freezes?
- Salt makes water heavier
- Salt lowers the freezing point of water
- Salt makes water warmer
A scientist puts a cup of fresh water and a cup of salty water in the same freezer at the same temperature. The fresh water freezes first. Why?
- Salty water freezes at a lower temperature
- Fresh water has more water vapour in it
- Salty water is heavier so it takes longer to cool
Divya says an iceberg is made of frozen salty ocean water, just like sea ice. Is she right?
- Yes, icebergs and sea ice are the same thing
- No, icebergs are made of water vapour
- No, icebergs are fresh-water glacier ice

Answer key

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

Solid, liquid, gas · Water can be ice (solid), water (liquid), or water vapour (a gas).
Sea ice · Sea ice forms when the ocean surface freezes.
True · Big chunks of glacier ice crack off and drift into the sea as icebergs.
It floats, same size weighs less · The same size piece weighs less than liquid water, so the cube floats on top, just like an iceberg floats in the ocean.
The thick, fresh-water chunk · Glacier ice is snow squeezed tight for hundreds of years, so it is fresh water and very thick. The thin, salty chunk is sea ice.
Salt lowers the freezing point of water · Salt gets in the way of water molecules locking together, so salty water needs a lower temperature to freeze.
Salty water freezes at a lower temperature · Because salt lowers the freezing point, the salty water must reach a lower temperature before it can freeze.
No, icebergs are fresh-water glacier ice · Icebergs break off from glaciers, so they are fresh water, not the salty frozen ocean water that makes sea ice.