Particulate pollutants include .......

Match the following:

List-$I$	List-$II$
$A$. Insecticide	$I$. $COD$
$B$. $K_2Cr_2O_7 / 50\% H_2SO_4$	$II$. $PAN$
$C$. Bleaching of clothes and paper	$III$. $Na_3AsO_3$
$D$. Eye irritant	$IV$. $BOD$
	$V$. $H_2O_2$

The correct answer is:

Give the examples of particulate pollutants.

Which of the following compounds is the most harmful component of photochemical smog?

Which of the following solvents reduces the environmental pollution?

Polar stratospheric clouds were observed over Antarctica some time ago. How might they have formed,and what happens if some of these clouds break down due to heat in the presence of sunlight?