$CFCl_3$ is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen?

State whether the following statements are true or false:
$(1)$ Mist is produced by particles of spread liquid and by condensation of vapour in air.
$(2)$ Particulate matter of size up to $5 \ \mu m$ reaches directly into the lungs.
$(3)$ Ozone and nitric oxide cause irritation in the nose and throat.

Biochemical Oxygen Demand $(BOD)$ is the amount of oxygen required (in $ppm$):

Which one of the following gases converts haemoglobin into carboxyhaemoglobin?

The chlorine free radical reacts with ozone to form a ..... free radical.

Photochemical smog is known as ...... smog.