Choose the correct alternative

1. Which of the following materials is not needed when burning a candle?

heat
wax
water
oxygen
fuel

2. Which of the following things is not needed when burning a candle?

heat
carbon dioxide
wax
oxygen
fuel

3. Which substance is always required in combustion reactions?

wax
wood
ash
charcoal
oxygen

5. What substance is produced when carbon reacts with oxygen?

carbon hydroxide
ash
nitrogen
carbon dioxide
dihydromonoxide