The $BOD$ values for pure water and highly polluted water are respectively

The gas $A$ has very low reactivity and reaches the stratosphere. It is non-toxic and non-flammable but is dissociated by $UV$ radiations in the stratosphere. The intermediates formed initially from the gas $A$ are:

What is green fuel? Give information about waste recycling.

The ions of $Ni, Hg, Ag, Pb, Zn$ etc.,are generated as waste from which industry?

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.

Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?