# NEET Chemistry The Solid State Questions Solved

BOARD

(a) Why does presence of excess of lithium makes LiCl crystals pink?

(b) A solid with cubic crystal is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound?

(a) This is due to metal excess defect due to anionic vacancies in which the anionic sites are occupied by unpaired electrons (F-centres).

(b) As atoms of Q are present at the 8 centres of the cube, therefore, number of atoms of Q in the unit cell =$\frac{1}{8}$$×$8 = 1

The atom P is at the body centre

$\therefore$ Number of atoms = 1

Ratio of atoms P : Q = 1 : 1

Hence, the formula of the compound is PQ.

Difficulty Level:

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