Which one of the following statements is an incorrect?

Options

A. The fraction of the total volume occupied by the atoms in a primitive cell is 0.48
B. Molecular solids are generally volatile
C. The number of carbon atoms in an unit cell of diamond is 4
D. The number of Bravais lattices in which a crystal can be categorised is 14

Answer

A

Explanation

`"Volume of atoms in a unit cell (V)"=(4)/(3)pi^(3)`
`"For primitive cell, r"=(a)/(2)`
`V=(4)/(3)pi((a)/(2))^(3)=(pia^(3))/(6)`
`"Volume of the unit cell (V)"=a^(3)`
Thus, total volume occupied by the atoms
`=("Volume of the atoms in unit cell")/("Volume of unit cell")`
`=(pia^(3))/(6)xx(1)/(a^(3))=(pi)/(6)=0.52=100-0.52=0.48`