An element has a body centered cubic structure with a unit cell edge length of 400 pm. Atomic mass of an element is `24 gmol^(-1)` What is the density of the element? `(N_A = 6 times 10^23 mol^-1)`

Options

A. `3.60 g cm^-3`
B. `1.80 g cm^-3`
C. `1.25 g cm^-3`
D. `2.50 g cm^-3`

Answer

C

Explanation

Answer(3) Density,`rho = (Z xx M) /(a^3 xx N_A`)
For BCC, Z =2 .
Atomic mass of element, M = 24 .
Edge length, a = 400pm =` 400 xx 10^-10 cm` .
`therefore rho = 2(24)/(400 xx 10^-10)^3(6 xx 10^23`).
`therefore Density, rho = 1.25 gcm^-3`.