Answer:
Therefore the theoretical density of iron is 7.877 g/cm³ .
Therefore the number of vacancy per cm³ is
Explanation:
BCC structure contains 2 atoms per cell.
BCC : Body centered cubic.
Atomic mass of iron = 55.845 gram/mole.
Atomic mass of a chemical element is the mass of 1 mole of the chemical element.
Density: Density of a matter is the ratio of mass of the matter and volume of the matter.
Avogrdro Number is number of atoms per 1 mole.
Avogrdro Number= 6.023×10²³
Lattice parameter of iron = 2.866×10⁻⁸ cm
The theoretical density:
g/cm³ [x= 2,Since it is BCC structure]
=7.877 g/cm³
Therefore the theoretical density of iron is 7.877 g/cm³ .
Now we have to find out the number of unit cell of iron crystal having density 7.874 g/cm³.
⇒ x =1.9923 atom/cell
Therefore the vacancy of atom per cell = (2- 1.9923)=0.0077
Therefore the number of vacancy per cm³ is