An element has density `6xx8"g cm"^(-3)` occurs in bcc structure with cell edge of 290 pm. Calculate the number of atoms present in 200 g of the element.

Explanation

`d=6.8"g cm"^(-3)`, z (b.c.c. lattice)
= 2 `a=290"pm"=2.9xx10^(-8)"cm"`,
m = 200 g, n = ?
`d=(Zxxm)/(a^(3)xxn)`
`n=(Zxxm)/(a^(3)xxd)=(2xx200g)/((2.9xx10^(-8))^(3)"cm"^(3)xx6.8"g cm"^(-3))`
`n=(400xx10^(24))/(24.39xx6.8)=2.4xx10^(24)`.