At room temperature, pollonium crystallizes in a primitive cubic unit cell. If a = 3.36 Å, calculate the theoretical density of pollonium, its atomic mass is 209 g `mol^(-1)`.

Explanation

A primitive cubic unit cell contains atoms only at the 8 corners with each corner contributing `1//8^(th)` of an atom . Hence n = `8 xx (1//8) = 1` . Volume `V = a^(3) = (3.36 Å)^(3)`
From Eq. 1 `rho = (n M m)/(N_(0) V)`
`= ((1) 209 g mol^(-1)))/((6.022 xx 10^(23) mol^(-1)) (3.36 xx 10^(-8) cm)^(3))`
`= 9.15 g cm^(-3)`