Calculate the density of unit cell of sodium, if the edge length of cubic structure is `4.24 A^(@)`.

Explanation

Density, `d=(ZxxM)/(d^(3)N_(0))`
   
  Z = Number of atoms per unit cell = 2
 (since Na crystallise in bcc lattice)  
M = Gram atomic mass of sodium `= 23 g mol^(-1)`  
`N_(0)` = Avogadro number `= 6.023 xx10^(23)`  
a = Edge length = 4.24 angstroms
`=4.24xx10^(-1)m`
Density `=(2(23xx10^(-3)))/(6.023xx10^(23)xx(4.24xx10^(-10))^(3))`
`=1.002xx10^(3)kgm^(-3)`