Question

Someone please briefly explain (A) and (B). What is the full form of PF and VF? (Class 11 Solid State).​

Answer 1

• PF is packing fraction and VF is void fraction.
• Packing fraction means the fraction of volume that is occupied by the constituent particles.
• According to your question BCC unit cell has the packing fraction of 0.68 which means 68 % of the volume is occupied by the atoms in BCC unit cell.
• Void fraction is the remaining fraction which is empty or not occupied by the atoms.
• If 68 % of the volume is occupied by the atoms then space that is not occupied by the atoms is (void space) = 100 -68 = 32 %.

Hope this helps you.