IMO Practice Test — Matter & Mixtures
6 Questions • 12 min • Olympiad level
12:00
Question 1 of 6
hard
Filtering muddy water makes it clear, but it may still be unsafe to drink because filtering does not remove tiny…
Germs
Stones
Leaves
Sand
Explanation: Filtering removes dirt but not germs, so we still boil it.
Question 2 of 6
hard
Sea water is a mixture because it is water with dissolved…
Iron bars
Salts and minerals
Stones
Wood
Explanation: Sea water mixes water with dissolved salts.
Question 3 of 6
hard
Changing state, such as ice to water, does not make a new substance because the ___ stays the same.
Name only
Colour
Container
Material (water)
Explanation: It is still water, just in a different state.
Question 4 of 6
hard
To separate a mixture of two liquids like water and oil that do not mix, we can use a…
Filter paper only
Magnet
Fan
Separating funnel (let them settle)
Explanation: Oil and water settle in layers and can be drained apart.
Question 5 of 6
hard
If you keep adding sugar to a glass of water, at some point no more dissolves. The water is then…
Frozen
Empty
Saturated (full)
Boiling
Explanation: When it can hold no more, the solution is saturated.
Question 6 of 6
hard
Why is a fruit salad a good example of a mixture you can easily separate?
It cannot be undone
The fruits melt together
It becomes one new fruit
You can still pick out each fruit
Explanation: Each fruit keeps its identity and can be picked out.