Question

. In a closely packed face centred unit cell will all lattice
positions occupied by 'A' atoms, body centred
octahedral hole is occupied by atom 'B' having
appropriate size. Choose the correct statement(s)
regarding such crystal:
1) Void percentage is 25
2) Percentage space occupied is 80.3
3) Formula of the compound is A B
4) Formula of the compound is AB​

Answer 1

Answer:

Zeffective of A= Face centre position =1/2×6×1/8 ×8=4

Zeffective of B=1+1/12×4=4 (Effective number of tetrahedral void)

Formula =A4 B4=AB