10. One of the metals below will react violently when put in water. Which one?

• A. Aluminium
• B. Copper
• C. Potassium
• D. Iron

11. Which of these lists has metals in the correct order from most reactive to least reactive?

• A. sodium, zinc, copper
• B. zinc, copper, sodium
• C. iron, sodium, copper
• D. sodium, copper, zinc

12-15. When iron pieces are added to copper sulfate, a reaction occurs and copper metal is left at the bottom of the tube:

12. Which sentence best describes why this happens?

• A. Iron is more reactive than sulphur.
• B. Iron is more reactive than copper.
• C. Copper is more reactive than sulphur.
• D. Copper is more reactive than iron.

13. What is the name given to this kind of reaction?

• A. Neutralisation reaction.
• B. Displacement reacton.
• C. Combustion.
• D. Thermal decomposition.

14. Which of these word equations correctly shows this reaction?

• A. iron + copper sulfate → copper + hydrogen + water
• B. iron + copper sulfate → copper + a salt + water
• C. iron + copper sulfate → copper + iron + sulfur
• D. iron + copper sulfate → copper + iron sulfate

15. The test tube in this experiment gets hot - the chemical reaction produces heat energy. What is this kind of reaction called?

• A. endothermic
• B. exothermic
• C. thermal decomposition
• D. neutralisation

16. If carbon is added to a metal oxide and heated, then it can displace the metal producing carbon dioxide and a pure metal.

However, only one of the reactions below can occur . Which one?

• A. carbon + sodium oxide → sodium + carbon dioxide
• B. carbon + magnesium oxide → magnesium + carbon dioxide
• C. carbon + aluminium oxide → aluminium + carbon dioxide
• D. carbon + iron oxide → iron + carbon dioxide