Question

If lattice parameter for a crystalline structure is 3.6 Å, then atomic radius in fcc crystal in Å is –

• A. 7.20 Å
• B. 1.80 Å
• C. 1.27 Å
• D. 2.90 Å

Answer 1

Answer: (C)

1.27 Å

Answer 2

Atomic radius for fcc crystal is r = $\frac{a}{2\sqrt{2}}$ = $\frac{3.6}{2\sqrt{2}}Å$ = 1.27 Å