What is the mass of a $bcc$ type unit cell of sodium if the mass of one atom of sodium is $3.819 \times 10^{-23} \ g$?

In sodium chloride crystal,the number of next nearest neighbours of each $Na^{+}$ ion is

$A$ 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:

How many atoms are there in a cubic unit cell having one atom on each corner and two atoms on each body diagonal of a cube?

If the length of the body diagonal of a cube is $x$,then the tetrahedral void will be at a distance of ....... from the center of the cube.

$A$ compound contains $Ca, Ti$ and $O$ elements. If $Ca^{2+}$ ions are at the corners of the cube,$Ti$ ions are at the body center,and $O^{2-}$ ions are at the face centers,then the molecular formula of the compound and the oxidation state of $Ti$ are respectively ........