Question

$Na$ and $Mg$ crystallise in BCC and FCC type crystals, then the number of $Na$ and $Mg$ atoms present in the unit cell of their respective crystal is

• A. 4 and 2
• B. 9 and 14
• C. 14 and 9
• D. 2 and 4

Answer 1

Answer: (D)

2 and 4

Answer 2

No. of atoms per unit cell in $BCC$ structure $= 2$ No. of atoms per unit cell in $FCC$ structure $= 4$