Question

Metal M crystallizes into a fcc lattice with the edge length of $4.0 × 10^{–8} cm$. The atomic mass of the metal is _______ g/mol. (Nearest integer)

(Use :$N_A=6.02×10^{23} mol^{-1}$,density of metal , $M = 9.03 g cm^{- 3}$)

Answer 1

a= 4×10-8 cm

d=9.03g/ml

$\frac{ZM}{N_Aa^3}$

$M= \frac{9.03×6.02×10^{23}×64×10^{-24}}{4}=86.97$ ≈ 87