Explain occurence of elements of group-15.

Explanation

(i) Nitrogen : Molecular nitrogen comprises 78% by volume of the atmosphere.
In the earth.s crust it occurs as sodium nitrate, `NaNO_3` (called chile saltpetre) and potassium nitrate, `KNO_(3)` (Indian saltpetre). It is found in the form of proteins in plants and animals.
(ii) (ii) Phosphorus : Phosphorus occurs in minerals of the apatite family `Ca_(9)(PO_(4))_(6).CaX_(2) (X =F,Cl or OH)`
For example: Fluoraptite `[Ca_(9)(PO_(4))_(6).CaF_(2)]`
Chlorapatite: `[Ca_(9)(PO_(4))_(6).CaCl_(2)]` and
Hydroxyapatite: `[Ca_(9)(PO_(4))_(6).Ca(OH)_(2)]` which are main components of phosphate rocks.
Phosphorus is an essential constituent of animal and plant matter . It is present in bones as well as in living cell. Phosphoproteins are present in milk and eggs.

(iii) Arsenic, antimony and bismuth are found mainly as sulphide minerals.
(iv) Moscovium is a synthetic radioactive element with atomic mass-289 and very short half-life period. Due to very short half life time, it is available in very litde amount.