Calculate the molar mass of an element with density $2.7 \ g \ cm^{-3}$ that forms $fcc$ structure. $\left[a^3 \cdot N_{A}=40 \ cm^3 \ mol^{-1}\right]$

$Cu$ metal crystallizes in an $fcc$ or $ccp$ lattice. If the edge length of its unit cell is $361 \ pm$, what is the radius of the $Cu$ atom (in $pm$)?

Calculate the edge length of the unit cell of a metal which crystallises in a $bcc$ structure. (Radius of metal atom $= 173 \ pm$)

An ionic solid $X^{+} Y^{-}$ crystallizes in a $bcc$ structure. If the distance of the closest approach between the two ions is $173 \ pm$, what is the edge length of the unit cell in $pm$?

The diffraction pattern of a crystalline solid gave a peak at $2 \theta = 60^{\circ}$. What is the distance (in $cm$) between the layers which gave this peak? ($\lambda$ of $X$-rays is $1.54 \mathring{A}$) ($\sin 30^{\circ} = 0.5$,$\sin 60^{\circ} = 0.866$; $n = 1$)

An element has a $bcc$ structure. If its edge length is $250 \, pm$ and its density is $8 \, g/cm^3$,calculate its molar mass and the radius of the atom.