Question

In the zinc blende structure , zinc ions occupy alternate tetrahedral voids and s2- ions exists as ccp. The radii of zn 2+ and s2- ions are 0.83 a and 1.74 a respectively. Then the edge length of the zn unit cell is

Answer 1

Answer:

The options given are:

• 2.57 Å

• 5.14 Å

• 2.96 Å

• 5.94 Å

Solution :

Let us solve this question step by step:

Zinc Ions occupy alternate tetrahedral voids,  

and, s2- ions exists as ccp

Given that - radii of zn 2+ and s2- ions are 0.83 a and 1.74 a respectively.

r+r−r+r- gt0.414  ⇒ a=43–√(r++r−)

=43–√(0.83+1.74)

=5.935Å≈5.94Å

Hence, the Answer is D, that is  5.94Å