For a crystal, the angle of diffraction $(2 \theta)$ is $90^{\circ}$ and the second order line has a $d$ value of $2.28 \ \text{Å}$. The wavelength (in $\text{Å}$) of $X$-rays used for Bragg's diffraction is

In $CsCl$ type structure, if the radius of the cation and anion are $80 \ pm$ and $100 \ pm$ respectively, then the closest distance between two cations is:

$A$ metal crystallises in two phases,one as $fcc$ and other as $bcc$ with unit cell edge lengths of $3.5 \ \mathring{A}$ and $3.0 \ \mathring{A}$ respectively. The ratio of density of $fcc$ and $bcc$ phases approximately is

The crystal structure of an element has an $fcc$ lattice. If the edge length of the crystal is $4 \ \mathring{A}$,what is the atomic weight (in $g \ mol^{-1}$) of the element,if the density of the crystal is $11.21 \ g \ cm^{-3}$ $(N_{A} = 6.023 \times 10^{23} \ mol^{-1})$?

Ammonium chloride crystallizes in a body-centered cubic lattice with an edge length of the unit cell of $390 \ pm$. If the size of the chloride ion is $180 \ pm$,the size of the ammonium ion would be ........... $pm$.

What are the variables in the graph of powder diffraction pattern of a crystalline solid?