Question

A mineral having the formula `AB_(2)` crystallizes in the `ccp` lattice, with `A` atoms occupying the lattice points. Select the correct statement(s).
A. The coordination number `(CN)` for `A` atoms `= 8`.
B. The `CN` for `B` atom `= 4`
C. `100%` of `TV_(s)` are occupied by `B` atoms
D. `50%` of `TV_(s)` are occupied by `B` atoms.

Answer 1

Correct Answer - A::B::C
Number of atoms `= 4` (for ccp crystal)
Formula `= 4AB_2 = A_4B_8`
`:. CN` of `A =8`[`CN` of `A =` Number of `B` atoms]
`CN` of `B= 4` [`CN` of `B =` Number of `A` atoms]
In ccp arrangment, all `TVs` are occupied (fluorite-type structure).