The density of a face centered cubic element is `6.25 g cm^(-3)`. Calculate the length of the unit cell . (Atomic mass of the element = 60.2 amu).

Explanation

Given Z = 4 , M = 60.2 amu , `rho = 625 g cm^(-3)`
`N_(A) = 6.023 xx 10^(23)`
Applying the formula :
` a^(3) = (Z xx M)/( rho xx N_(A))`
` = (4 xx 60.2)/(6.25 xx 6.023 xx 10^(23))`
` a = ((4 xx 60.2)/(6.25 xx 6.023 xx 10^(23)))^(1)/(3)`
` = 400 xx 10^(-10) cm`
= 400 pm