Moldydenum `("At. mass=96g//mol"^(-1))` crystallizes as bcc crystal. If density of crystal is `10.3g//cm^(3)`, then radius of Mo atoms `(use N_(A)= 6 xx 10^(23))`:

Options

A. 111 pm
B. 314 pm
C. 135.96 pm
D. none of these

Answer

C

Explanation

`d = (zM_w)/(N_A a^3)`
`Z = 2 , M_w = 96, d = 10.3 g//cm^3`
`sqrt3a = 4r = (sqrt3 a)/(4)`
` a^3 = (2 xx 96)/(10.3 xx 6.023 xx 10^23) = 3.14 xx 10^(-8)`
` r = (sqrt3a)/(4) = (sqrt3 xx 3.14 xx 10^(-8))/(4) = 135.96` pm