Question

Sodium crystallizes in a cubic lattice. The edge of the unit cell is 4.3 Angstrom, density of Sodium is 963 kg per cubic meter & its atomic weight is 23. What type of unit cell does Sodium form?​

Answer 1

We know that,

Density-

d=a3×NAZ×M

Given :

Molar Mass(M)=108g/mol

Density (d)=10.5g/cm3

Edge Length(a)=409pm

Z=Md×a3×NA

Value of NA is NA=6.023×1023

Z=10810.5×(409×10−10cm3)3×6.023×1023=4

Number of atoms =4

Hence the element is packed in FCC structure.