The relationship between the radius $(r)$ of the atom and the edge length $(a)$ of the cubic close packing $(CCP)$ structure is:

Which of the following lattices has the highest packing efficiency: $(i)$ simple cubic,$(ii)$ body-centred cubic,and $(iii)$ hexagonal close-packed lattice?

$A$ solid compound is formed by atoms of $A$ (cations),$B$ (cations),and $O$ (anions). Atoms of $O$ form an $hcp$ lattice. Atoms of $A$ occupy $25\%$ of the tetrahedral voids,and atoms of $B$ occupy $50\%$ of the octahedral voids. What is the molecular formula of the solid?

Show that in a cubic close packed $(ccp)$ structure,eight tetrahedral voids are present per unit cell.

Atoms of an element $Z$ form a hexagonal closed packed $(hcp)$ lattice and atoms of element $X$ occupy all the tetrahedral voids. The formula of the compound is

In a face-centred cubic arrangement of $A$ and $B$ atoms,$A$ atoms are at the corners of the unit cell and $B$ atoms are at the face centres. If three of the $B$ atoms are missing from the face centres in the unit cell,what is the simplest formula of the compound?