Calculate the radius of an atom of metal if it forms a simple cubic unit cell with an edge length of $380 \ pm$. (in $pm$)

What is the density of an element (At. mass $100 \ g \ mol^{-1}$) having $BCC$ structure with edge length $400 \ pm$ (in $g \ cm^{-3}$)?

The unit cell of an element has an edge length of $5 \mathring{A}$ and a density of $4 \ g \ cm^{-3}$. If its atomic mass is $149 \ g \ mol^{-1}$,identify the crystal structure.

Copper crystallises in a $ccp$ arrangement and the accepted value of the metal ion radius was found to be $1.28 \ \mathring{A}$. Calculate the density of copper in grams per cubic centimetre. (Atomic weight of copper is $63.5 \ g/mol$, $N_A = 6.022 \times 10^{23} \ mol^{-1}$) (in $g/cm^3$)

When an electron in an excited atom jumps from the $L$ shell to the $K$ shell,$X$-rays are emitted. These $X$-rays undergo first-order diffraction at an angle of $7.75^{\circ}$ by a crystal with an interplanar spacing of $2.64 \ \mathring{A}$. Calculate the energy difference between the $K$ shell and the $L$ shell. $(\sin \ 7.75^{\circ} = 0.1349)$

An element has a $bcc$ structure with a cell edge of $288 \ pm$. The density of the element is $7.2 \ g \ cm^{-3}$. What is the atomic mass of the element?