Question

A compound is formed by atoms of elements A occupying the corners of the unit cell and an atom of element B present at the center of the unit cell. Deduce the formula of the compound.

(a) AB2

(b) AB3

(c) AB4

(d) AB

The question was posed to me during an interview for a job.

My question comes from Solid State in division Solid State of Chemistry – Class 12

Answer 1

Correct option is (d) AB

For explanation I would say: The description is of a BCC. For BCC, each atom at the corner is shared by 8 unit cells. One atom at the center wholly belongs to the corresponding unit cell.

Therefore, total number of atoms of A present=\(\frac{1}{8}\) x 8=1

Total number of atoms of B present=1

Therefore, A:B=1:1 implying the formula of the compound is AB.