Aluminium crystallizes in a ccp structure. Its metallic radius is 125pm. The number of unit cells in 1.00 `cm^(3)` of Al are

Options

A. `2.27 xx 10^(22)`
B. `1.13 xx 10^(20)`
C. `2.26 xx 10^(26)`
D. `1.13 xx 10^(23)`

Answer

A

Explanation

For ccp structure
`a = 2 sqrt(2) r = 2 xx 1.414 xx 125 = 353.5 `pm
or `353.5 xx 10^(-10) `cm
Volume of unit cell `= ( 353.5 xx 10^(-10))^(3)`
`= 4.42 xx 10^(23) cm^(3)`
No. of unit cells in 1 `cm^(3)`