Nickel crystallises in a $fcc$ type of unit cell,with edge length $0.3524 \ nm$. Calculate the radius of nickel atom. (in $nm$)

Identify the instrument used to determine the crystal structure from the following:

Niobium crystallises in a body-centred cubic $(bcc)$ structure. If the density is $8.55 \, g \, cm^{-3}$,calculate the atomic radius of niobium using its atomic mass $93 \, u$.

In an $NaCl$ crystal, the radii of $Na^{+}$ and $Cl^{-}$ ions are $95 \, pm$ and $180 \, pm$ respectively. The edge length of its unit cell is ........... $pm$.

Calculate the density of a metal having a unit cell volume of $64 \times 10^{-24} \ cm^3$ and a molar mass of $192 \ g \ mol^{-1}$,containing $4$ particles per unit cell. (in $g \ cm^{-3}$)

$A$ metal has a cubic lattice of side length $2.88 \, \mathring{A}$. The density of the metal is $7.2 \, g/cm^3$. How many unit cells are present in $7.2 \, mg$ of the metal?