Answer:
Option B
Explanation:
Given ,
Cell in bcc, so Z=2
Edge length (a) =288 pm
=288 X 10-8 cm
Density of metal (d) = 7.2 g cm-3
NA= 6.022 x 1023
We know that , density (d)= $\frac{Z \times M}{a^{3}.N_{A}}$
$\therefore M=\frac{d.a^{3}.N_{A} }{Z}$
$=\frac{7.2\times (2.88\times 10^{-8})\times6.022\times 10^{23}}{2}$
$=\frac{7.2\times 23.8878\times 10^{-24}\times6.022\times 10^{23}}{2}$
= 51.78 g mol-1