If three elements P, Q and R crystallise in a cubic unit cell with P atoms at the corners, Q atoms at the cubic centre and R atoms at the centre of each face of the cube, then write the formula of the compound.

Answer

`PQR_3`

Explanation

Atoms P per unit cell = 8 x 1/8=1, Atoms Q per unit cell =1, Atoms R per unit cell = 6 x 1/2=3
Hence, the formula is `PQR_3`