Question

An element A crystallises in fcc structure. 200 g of this element has `4.12 xx 10^24` atoms The density of A is `72 cm^(-3)`. Calculate the edge length of the unit cell.

Answer 1

Correct Answer - 299.9 pm
`rho=(Zxxm)/(a^3xx10^(-30))"or" a=((Zxxm)/(rhoxx10^(-30)))^(1//3)=(4xx200//(4.12xx10^24))/(7.2xx10^(-30))"pm"`=299.9 pm