How many particles per unit cell are present in $BCC$ structure?

In a mineral $MX_2$,$M^{+2}$ ions are arranged in a $ccp$ structure and $X^{-}$ ions occupy the tetrahedral voids. What are the number of cations and anions per unit cell,the coordination number of the cation,and the percentage of occupied tetrahedral voids,respectively?

Calculate the total number of atoms in a $bcc$ crystal lattice containing $2 \times 10^{23}$ unit cells.

The unit cell of diamond is composed of:

$Na$ and $Mg$ crystallise in $b.c.c.$ and $f.c.c.$ type crystals respectively. The number of atoms of $Na$ and $Mg$ present in the unit cell of their respective crystals is:

Potassium crystallizes in a $bcc$ lattice. What is the coordination number of potassium in the potassium metal?