# NEET Chemistry The Solid State Questions Solved

The unit cell of a metallic element of atomic mass 108 and density 10.5 g/$c{m}^{2}$ is a cube with edge length of 409 pm. The structure of the crystal lattice is-

(A) fcc

(B) bcc

(C) hcp

(D) None of these

(A). $\rho =\frac{Z×M}{N×{a}^{3}};$ Here, M=108, ${N}_{A}=6.023×{10}^{23}$

Put on these values and solving we get

a= 409pm = $4.09×{10}^{-8}cm$$\rho =10.5g/c{m}^{2}$

z = 4 = number of atoms per unit cell.
So, the structure of the crystal lattice is fcc.

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