Gold has a face-centered cubic $(fcc)$ lattice with an edge length of the unit cube of $407 \, pm$. The diameter of the gold atom is .............. $pm$.

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

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?

Sodium crystallizes in $bcc$ structure with radius $1.86 \times 10^{-8} \text{ cm}$. What is the edge length of unit cell of sodium?

An ionic solid $X^{+} Y^{-}$ crystallizes in a $bcc$ structure. If the distance of the closest approach between the two ions is $173 \ pm$, what is the edge length of the unit cell in $pm$?

An element (atomic mass $100 \ g/mol$) having $bcc$ structure has unit cell edge $400 \ pm$. Then density of the element is (in $g/cm^3$)