P Q

Inhaled air Exhaled air

Measuring cylinder

Cork

Water

Burning candle

Diagram 1

Diagram 1 shows an activity to compare the content of oxygen in inhaled air and exhaled air.

(a) (i) Which candle will burn for a longer time? ……………………………………………………………………………………………………

[1 mark]

(ii) Explain your answer in (a)(i)

………………………………………………………………………………………………….. [1 mark]

(b) (i) During the burning of the candle, which component of the air does not change in volume?

……………………………………………………………………………………………………

[1 mark] (ii) Give one reason for your answer in (b)(i).

........................................................................................................................................[1 mark]

(c) During the haze, the Air Pollutant Index is above 500 which is a sign that the air is bad for health.

(i) State one human activity that causes the haze.

....................................................................................................................................... [1 mark]

(ii) Suggest what you should do if you have to go out of your house during the haze.

…………………………………………………………………………………………………..

[1 mark]