The cubic unit cell of $\mathrm{Al}$ (molar mass $=27 \mathrm{g} {\mathrm{mol}}^{-1}$) has an edge length of $405 \mathrm{pm}$. Its density is $2.7 \mathrm{g} {\mathrm{cm}}^{-3}$. The cubic unit cell is

A compound ${\mathrm{M}}_{\mathrm{p}}{\mathrm{X}}_{\mathrm{q}}$ has cubic close packing (CCP) arrangement of $\mathrm{X}$. Its unit cell structure is shown below. The empirical formula of the compound is

The unit cell with the following structure refers to______crystal system.

The crystal system of a compound with unit cell dimensions $\mathrm{a}=0.387, \mathrm{b}=0.387 \text{and} \mathrm{c}=0.504 \mathrm{nm}$ and $\mathrm{\alpha }=\mathrm{\beta }=90º \text{and} \mathrm{\gamma }=120º$ is

In a bcc unit cell, atoms are numbered as shown below. The atoms touching each other are: