IMO Practice Test — Matter & Its Changes
6 Questions • 12 min • Olympiad level
12:00
Question 1 of 6
hard
Evaporation and condensation together keep happening in nature as part of the…
Light cycle
Food chain
Water cycle
Day cycle
Explanation: These changes drive the water cycle.
Question 2 of 6
hard
A balloon can be squeezed smaller because the gas inside has particles that are…
Solid
Tightly packed
Frozen
Far apart and can be pushed closer
Explanation: Spread-out gas particles can be pressed closer together.
Question 3 of 6
medium
Why can a liquid be poured but a solid cannot?
Liquids are colder
Solids are heavier
Liquid particles can slide past each other
Solids are wet
Explanation: Liquid particles slide and flow; solid ones stay fixed.
Question 4 of 6
hard
Mixing flour, water and baking it into a cake is irreversible because a ___ substance is formed.
Cold
New
Frozen
Wet
Explanation: Baking forms a new substance that cannot be un-baked.
Question 5 of 6
hard
Different solids melt at different temperatures; butter melts easily but iron needs very great…
Light
Cold
Heat
Sound
Explanation: Iron needs far more heat to melt than butter.
Question 6 of 6
hard
A mixture of sand and water can be separated by ___ because sand does not dissolve.
Filtering
Boiling away the sand
Freezing
Burning
Explanation: Filtering catches the undissolved sand.