Respuesta :

Answer : The density is, [tex]3.60g/cm^{3}[/tex]

Explanation :

Formula used :  

[tex]\rho=\frac{Z\times M}{N_{A}\times a^{3}}[/tex] .............(1)

where,

[tex]\rho[/tex] = density  = ?

Z = number of atom in unit cell (for BCC = 2)

M = atomic mass  of barium = 137.3 g/mole

[tex](N_{A})[/tex] = Avogadro's number =  [tex]6.022\times 10^{23} mol^{-1}[/tex]

a = edge length of unit cell  = [tex]5.02\AA=5.02\times 10^{-8}cm[/tex]

Conversion used : [tex](1\AA=10^{-8}cm)[/tex]

Now put all the values in above formula (1), we get

[tex]\rho=\frac{2\times (137.3g/mol)}{(6.022\times 10^{23}mol^{-1}) \times (5.02\times 10^{-8}cm)^3}=3.60g/cm^{3}[/tex]

Thus, the density is, [tex]3.60g/cm^{3}[/tex]