The edge length of a face-centered cubic unit cell of an ionic substance is $508 \ pm$. If the radius of the cation is $110 \ pm$, what is the radius of the anion in $pm$?

Potassium crystallizes with a

Body centered cubic lattice has a coordination number of

$A$ solid compound contains atoms $X, Y,$ and $Z$. In its unit cell,atoms $X$ are at the corners,atoms $Y$ are at the body center,and atoms $Z$ are at the face centers. The formula of the compound is:

What is the two-dimensional coordination number of a molecule in a square close-packed layer?

$A$ crystal is made up of metal ions $M_1$ and $M_2$ and oxide ions. Oxide ions form a $ccp$ lattice structure. The cation $M_1$ occupies $50 \%$ of octahedral voids and the cation $M_2$ occupies $12.5 \%$ of tetrahedral voids of the oxide lattice. The oxidation numbers of $M_1$ and $M_2$ are,respectively: