In a solid state, Nitrogen occurs as
(A) Chile saltpeter
(B) Saltpeter
(C) Sal ammoniac
(D) All of these.

Hint: In order to answer the question, we must be knowing about the occurrence of Nitrogen in the solid state. Nitrogen is a chemical element which is represented by the symbol ‘N’ and will be having an atomic number of Z = 7.

Complete solution:
Let us first understand about Nitrogen. Nitrogen is a chemical element which is having an atomic number of 7 and is represented by the symbol ‘N’. Nitrogen belongs to the p- block element and is the lightest member of Group 15 (VA) in the periodic table. The electronic configuration of Nitrogen is \[1{s^2}2{s^2}2{p^3}\]. The number of valence electrons present in it is 5. Nitrogen is the most abundant chemical element present in the earth’s atmosphere which is around 81%. Nitrogen atoms are colourless and odourless in nature. In the solid state, Nitrogen is present as Saltpeter, Chile Saltpeter and Sal ammoniac. Saltpeter is the potassium nitrate with the chemical formula of \[KN{O_3}\], Chile saltpeter is the sodium nitrate with the chemical formula of \[NaN{O_3}\] and Sal ammoniac is ammonium chloride with the chemical formula of \[N{H_4}Cl\].

Note: Let us see some of the uses of Nitrogen:
- Nitrogen is used for the manufacture of ammonia.
- It is used to produce fertilisers.
- Nitrogen is crucial for life as it is present in the RNA and DNA.
- liquid Nitrogen is used for the freezing purposes.