A metallic element exists as simple cubic lattice. Each edge of the unit cell is `3Å` . The density of the metal is `9 "g cm"^(-3)` . How many number of unit cells will be present in 100 g of the metal : -

Options

A. `6.85 xx10^(2)`
B. `4.12 xx10^(23)`
C. `4.37 xx10^5`
D. `2.12 xx10^6`

Answer

B

Explanation

C. D.`=(ZxxM_w)/(VxxN_A) = (ZxxM_0)/(VxxN_0)`
Number of unit cell present in `100 g of ` the metal `= M_0/(VxxC.D.)=100/(3xx10^(-8))xx9`
`= 4.12 xx 10^(23)`