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

$A$ compound is formed by elements $A$ and $B$. Element $A$ occupies the corners of the cube,and element $B$ occupies the face centers. What is the formula of the compound?

Calculate the volume of a unit cell having an atomic radius of $141.4 \ pm$ forming an $fcc$ unit cell.

An alloy of gold and copper crystallizes in a cubic lattice in which the gold atoms occupy the lattice points at the corners of a cube and copper atoms occupy the centers of each of the cube faces. Determine the formula of this compound.

In $CsCl$ structure,the coordination number of $Cs^{+}$ is

$Pt$ has an $FCC$ structure with an edge length of unit cell $392 \text{ pm}$. What is the radius of $Pt$ (in $\text{ pm}$)?