Solid StateHard
Question
A mineral having the formula AB2, crystallises in the cubic close - packed lattice, with the A atoms occupying the lattice points. The co-ordination number of the A atoms, that of B atoms and the fraction of the tetrahedral sites occupied by B atoms are
Options
A.8, 4, 100%
B.2, 6, 75%
C.3, 1, 25%
D.6, 6, 50%
Solution
It is fluorite (CaF2) structure. Since formula is AB2
⇒ No. of B atoms is twice the no. of A atoms. Hence B occupies all the tetrahedral voids (100%).
AB2 is (8 : 4) compound (Fluorite Structure Compound)
↓ ↑
C.N. of AC.N. of B.
⇒ No. of B atoms is twice the no. of A atoms. Hence B occupies all the tetrahedral voids (100%).
AB2 is (8 : 4) compound (Fluorite Structure Compound)
↓ ↑
C.N. of AC.N. of B.
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