Describe simple experiment to show that:

A burning candle produces water vapour and ${\mathrm{CO}}_2$.

Describe a simple experiment to show that:

There is an increase in weight when a candle burns.

Describe a simple experiment to show that:

The products of combustion of phosphorus weigh more than the phosphorus used.

Give two reasons to explain why air is a mixture and not a compound.

Explain how the percentage by volume of oxygen and carbon dioxide in the air is maintained at about $21\%$ and $0.03\%$ respectively.

Air contains nitrogen and oxygen. Name two other gases present in the air.

What are combustible and non-combustible substances?

Name two substances other than oxygen that support combustion.

Compare the burning of carbon compounds with respiration. How is respiration similar to burning?