Solid State question bank (Chemistry)

An atomic substance A of molar mass $12 \mathrm{g} {\mathrm{mol}}^{–1}$has a cubic crystal structure with edge length of $300\mathit{ }\mathrm{pm}$. The no. of atoms present in one unit cell of A is

(Nearest integer)

Given the density of A is $3.0 \mathrm{g} \mathrm{m} {\mathrm{m}}^{-1}$ and ${\mathrm{NA}}_{\mathrm{A}}=6.02\times {10}^{23} {\mathrm{mol}}^{-1}$

Which of the following represents the lattice structure of ${\mathrm{A}}_{0.95}\mathrm{O}$ containing ${\mathrm{A}}^{2+}, {\mathrm{A}}^{3+}$ and ${\mathrm{O}}^{2–}$ ions?

A.

B.

C.