Question

Platinum crystallizes in FCC crystal with unit length of 3.9231 Å. Calculate the density and atomic radius of platinum. (Atomic mass of Pt = 195.08) 

Answer 1

Given: Edge length (a) = 3.9231 Å 

 = 3.9231 x 10⁻⁸ cm 

 Atomic weight of Pt (M)= 195.08 

 z = 4 (FCC) 

 Avogadro’s number = N_A = 6.023 x 10²³ 

To find: Density (d) = ? 

 Atomic radius (r) = ? 

Formula: 

i. V = a³