6. Why do metals rust?
- because it has been exposed to too much carbon dioxide
- because the metal has lost oxygen (reduction)
- because the metal is being oxidised (gain of oxygen)
- because it has been exposed to too much water
7. How do indigestion tablets work?
- Contain bases like calcium carbonate to neutralise stomach acid
- Kills bacteria in stomach
- Replaces excess stomach acid with hydrochloric acid in tablet
8. Which method would be used to extract iron from its metal ore?
- heating with carbon
- electrolysis
9. What is the name of a smart alloy used in glasses frames and to repair damaged blood vessels?
- nitinol
- steel
- iron
10. Describe acids on the PH scale.
- PH number 8-14. purple
- PH number 0-6, purple
- PH number 0-6, red
- PH number 8-14, red
11. Metal carbonates give which products?
- salt + hydroxide
- salt + water + carbon dioxide
- salt
- salt + water
12. Why might metals be ideal for a saucepan base?
- metals are good conductors of electricity
- good conductors of heat
- metals are malleable
13. What method would be used to extract magnesium?
- electrolysis
- heating with carbon
14. What are the properties of aluminium?
- strong, hard, high melting point, conducts electricity
- low density, corrosion resistant, forms strong alloys
- shiny and easy to bend,unreactive
15. What is the test for chlorine?
- bleaches damp litmus paper
- relights a glowing splint
- makes a squeaky pop with a lighted splint