Potassium crystallizes in a $bcc$ lattice,hence the coordination number of potassium in potassium metal is

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

In a face-centred cubic $(FCC)$ unit cell,what fraction of the edge length is not covered by the constituent atoms?

$NaCl$ is a $FCC$ lattice where $Na^{+}$ ions are at corner and face centre positions. Chloride ions are at edge centres and body centre positions. How many $NaCl$ formula units will be in a unit cell?

In $NaCl$ the centres of two nearest like charged ions are present at a distance of

If the radius ratio limit is $0.414 - 0.732$,what will be the coordination number?