# At room temperature ,sodium crystallises in a body-centred cubic lattice with $a=4.24A^{\large\circ}$.The theoretical density of sodium (At.wt of Na=23) is ?
$\begin{array}{1 1}1.002gcm^{-3}\\2.002gcm^{-3}\\3.002gcm^{-3}\\4.002gcm^{-3}\end{array}$