Question

`Zn` converts from its melted state to its soilds state, it has hcp structure ,thenfind out the number of nearest atoms.
A. `6`
B. `8`
C. `12`
D. `4`

Answer 1

Correct Answer - 3
`ABAB…` type is hexagonal closest packing `(HCP)`. In `HCP` stacking ,each spher is in contact with `6` other spheres in its own layer. it also touches directly `3` spheres in then layer above and three spheres in the layer below,Thus a sphere has `12` closet neighbours.