Question

An element crystallises in fcc lattice having edge length 350 pm.Maximum radius of the atom which can be placed in the

Answer 1

In fcc, interstitial sites will be octahedral voids and tetrahedral voidsFor tetrahedral voidsr1/r2 = 0.225For octahedral voids r1/r2 = 0.414 where r1 → radius of atom in interstitial sites r2 → radius of atom arranged in fcc  so  4r2 = √2 a

SEE THE IMAGE ☝️