An element has a bcc structure with a celledge of `288` pm. The density of the element is `7.2 g cm^(-3)`. How many atins are present in `208 g` of the element?

Explanation

For the BCC structure, Z=2
Edge of the unit cell , a=288 pm , Density of the element , `rho=7.2 g//cm^3`
Subtituting the values in the expression `rho=(ZxxM)/(a^3xxN_0)`
`7.2 g cm^(-3) =(2xxM)/((288xx10^(-10) cm)^3 xx(6.02xx10^23 mol^(-1))) "or" M=51.8 g mol^(-1)`
By mole concept, 51.8 g of the element contains =`6.02xx10^23` atoms
`therefore` 208 g of the element contains =`(6.02xx10^23)/51.8xx208` atoms =`24.17xx10^23` atoms