IMO Practice Test — Materials: Metals and Non-Metals
6 Questions • 15 min • Olympiad level
15:00
Question 1 of 6
Sodium is stored under kerosene oil because it:
Reacts vigorously with the moisture and oxygen in air
Floats on kerosene only
Is a non-metal
Conducts no electricity
Explanation: Sodium is so reactive it catches fire with air/water, so it is kept under kerosene.
Question 2 of 6
A piece of zinc is added to copper sulphate solution but copper is NOT added to zinc sulphate solution that reacts. This shows that:
Zinc is more reactive than copper
Copper is more reactive than zinc
Both are equally reactive
Neither reacts ever
Explanation: Only a more reactive metal displaces a less reactive one; zinc displaces copper, so zinc is more reactive.
Question 3 of 6
Why does food cooked in an iron pan add some iron to our diet but a copper vessel must be used with care?
Metals can slowly react with food; iron is helpful but excess copper salts are harmful
Iron is poisonous
Copper has no effect at all
Both metals are non-reactive
Explanation: Metals can react slightly with food; small iron is beneficial, but copper compounds in excess can be harmful.
Question 4 of 6
Sulphur dioxide gas dissolves in rain water to form acid rain. This is because the oxide of a non-metal is:
Acidic
Basic
Neutral
Metallic
Explanation: Non-metal oxides are acidic, so SO2 makes rain water acidic.
Question 5 of 6
Aluminium does not rust away like iron even though it is reactive, because:
A thin oxide layer forms and protects the metal underneath
Aluminium is a non-metal
Aluminium never reacts
Aluminium is a liquid
Explanation: A protective aluminium-oxide layer forms quickly and stops further reaction.
Question 6 of 6
Ornaments are made of gold and silver rather than iron mainly because gold and silver:
Are shiny and do not corrode easily
Are the cheapest metals
Are magnetic
Rust quickly
Explanation: Gold and silver stay lustrous and resist corrosion, so they suit jewellery.