The edge length of $fcc$ type unit cell of copper having atomic radius $127.6 \ pm$ is equal to (in $pm$)

An element has a body-centered cubic structure with a unit cell edge length of $400 \ pm$. The atomic mass of the element is $24 \ g \ mol^{-1}$. What is the density of the element (in $g \ cm^{-3}$)? $(N_{A} = 6 \times 10^{23} \ mol^{-1})$

Select the $INCORRECT$ option regarding the cubic crystal system-

Which of the following expressions is correct in the case of a $CsCl$ unit cell (edge length,$a$)?

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

An element crystallises in a $fcc$ lattice with cell edge $250 \ pm$. Calculate the density of the element (atomic mass $= 90.3 \ g \ mol^{-1}$) (in $g \ cm^{-3}$)