Question

AB has NaCl type ideal structure. If edge length of
crystal lattice is 282 Å. The radius of A* (approx) is
20.6
41.2 A
32 Å
28.3​

Answer 1

NaCl type lattice is fcc.

By geometry,

Radius of B=

$4r = \sqrt{2} a$

=> r = 1.44×282/4 = 101.5 A°.

Radius of A = 0.414×r = 0.414×101.5 =41.2A°.

Explanation:

A occupies all the octahedral voids and B occupies all the lattice points.

Radius of octahedral void =0.414× Radius of atom at the lattice point.