A face centered cubic element (atomic mass =60) has edge length of 400pm. What is the density of unit cell

Explanation

Given
`a = 300 pm = 300 xx 10^(-10) m`
No. of atoms in the unit cell, Z = 2
Atomic mass of the element, M = ` 60 g mol^(-1)`
we know, Density ` =(Z xx M)/(a^3 xx Na)`
`a^3 = 27000000 xx 10^(-30) cm`
`rho = (2 xx 50)/(27000000 xx 10^(-30) xx (6.022 xx 10^23 mol^(-1)))`
`rho = 100/(162594000 xx 10^(7))`
`rho = 6.15 g cm^3`