Question

The edge length of unit cell of a metal having molecular
weight 75 g/mol is 5Å which crystallizes in cubic lattice. If
the density is 2g/cc then find the radius of metal atom.
(NA = 6 × 10²³). Give the answer in pm.
(a) 217 pm (b) 210 pm
(c) 220 pm (d) 205 pm

Answer 1

Explanation:

the answer in pm is 217 pm

Answer 2

Answer:

answer is 217pm

Explanation:

for bcc

r=$\sqrt 3$/2a

d=z*m/N*$a^{3}$

here we have given

d=2g/cc

m=75g/mol

a=500*$10^{-12}$m

a=500pm

N=6.022*$10^{23}$

now put the value in above  eqn.

z=d*N*$a^{3}$/m

z=2*6.022*$10^{23}$*(500)^3/75

z=2

therefore metal crystal is bcc structure and for bcc lattice

$\sqrt{3}$a=4r

r=$\sqrt{3}$a/4

r=$\sqrt{3}$*500/4

r=216.25pm

there fore ans is 217pm