An element cyrstallizes in a structure having F.C.C. unit cell of an edge 200pm. Calculate the density if 200gm of it contains `24xx10^(23)` atoms

Options

A. 50.3 g/cc
B. 63.4 g/cc
C. 41.6 g/cc
D. 34.8 g/cc

Answer

C

Explanation

a = 200 pm ` = 2 xx 10^(-8) cm`
mass of unit cell ` = (200 xx 4)/(24 xx 10^23) = 33. 3 xx 10^(-23) g`
Density `m/v = (33.3 xx 10^(-23) )/(8 xx 10^(-24) ) = 41.6 ` g/cc