Which of the following compounds is likely to show both Frenkel and Schottky defects in its crystalline form?

The ratio of number of atoms present in a simple cubic, body centered cubic and face centered cubic structure are, respectively :

An element has a face-centred cubic (fcc) structure with a cell edge of $$a$$. The distance between the centres of two nearest tetrahedral voids in the lattice is :

10 mL of 1mM surfactant solution forms a monolayer covering 0.24 cm² on a polar substrate. If the polar head is approximated as cube, what is its edge length?