The density of $Na$ is $0.613 \ g \ cm^{-3}$. If the edge length of the unit cell of $Na$ is $5 \ \mathring{A}$,the effective number of atoms of $Na$ per unit cell is (Atomic weight of $Na = 23 \ u$)

For a crystal,the diffraction angle for the second-order diffraction is $2\theta = 90^{\circ}$. If the distance between two parallel planes is $2.28 \ \mathring{A}$,then the wavelength of the $X$-rays used for Bragg diffraction (in $\mathring{A}$) will be .........

Calculate the number of unit cells in $10 \, g$ of $CsCl$ which crystallizes in a $bcc$ structure. $(CsCl = 168.5 \, amu)$

Find the radius of an atom in $fcc$ unit cell having edge length $405 \ pm$. (in $pm$)

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 $g/cm^3$)

If $TlCl$ crystallizes in a $bcc$ structure,then the sum of the radii of the cation and anion will be ........ ($a =$ edge length).