`X`-rays diffraction studies show that copper crystallizes in an fcc unit cell with cell edge of `3.608 xx 10^(-8) cm`. In a separte experiment, copper is determined to have a density of `8.92 g cm^(3)`. Calculate the atomic mass of copper.

Options

A. 61.3 u
B. 62.3 u
C. 63.1 u
D. 64.1 u

Answer

C

Explanation

In case of fcc lattice , number of atoms per unit cell ,
Z=4 atoms.
`therefore M=(dN_Aa^3)/(Z)`
`=(8.92gcm^3xx6.022xx10^23 "atom mol"^(-1) xx (3.608xx10^(-8) cm)^3)/(4"atom")`
`=63.1gmol^(-1)`
`therefore` Atomic mass of copper (Cu) = 63.1u.