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).

At room temperature, pollonium crystallizes in a primitive cubic unit

1.	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).
Answer» Solution : 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)`