Compounds and mixtures - Test Bite

1. How many different atoms are there in a compound?

one
always two
two or more

2. Does this show an element, a mixture or a compound?

compound
mixture
element

3. Which statement about atoms and molecules is correct?

elements always exist as separate atoms.
elements always exist as pairs of atoms called molecules.
elements and compounds can exist as molecules.

4. Is water an element, compound or mixture?

element
compound
mixture

5. Which is the best way to get salt from salty water?

evaporation
filtration
distillation

6. Pure water can be separated from inky water by simple distillation. This is because:

water and ink have different boiling points.
water evaporates leaving the ink particles behind.
ink evaporates leaving the water behind.

7. What is the correct order for obtaining salt from a mixture of sand and salt?

dissolving in water - filtration - evaporation
evaporation - filtration - dissolving in water
filtration - dissolving in water - evaporation

8. Which method is usually used to separate coloured substances from each other?

simple distillation
evaporation
chromatography

9. Which of these three metals is the most reactive: potassium, iron or gold?

potassium
iron
gold

10. Which of these three metals is the least reactive: iron, copper or platinum?

iron
copper
platinum

11. Copper and oxygen react to form which compound?

copper oxygen
copper oxide
carbon dioxide