Argon crystallizes in the face-centered cubic arrangement at 40k. given that the atomic radius of argon is 191 pm, calculate the density of solid argon.

Molecular weight of 1 mole of Argon = 39.948 g

for face-centered cube = x = (√8) r and here r = 191 pm

so, x = √8 x 191 = 540 pm = 540 x 10 ^-10 cm

density = (39.948g / mol) x (unit cell / 540x10^-10 cm) ^3 x (mol / 6.022x10^23 atoms) x (4 atoms / unit cell) = 1.69g/cm^3

so density of solid argon is 1.69g/cm^3