JEE Main 2015 · 4 Apr · Shift 1 · Chemistry Q32

ChemistrySingle correct+4 / -1Question 32 of 90

Sodium metal crystallizes in a body centred cubic lattice with a unit cell edge of 4.29Å. The radius of sodium atom is approximately :

1.86Å

3.22Å

5.72Å

0.93Å

Answer and worked solution

Official answer: A

In bcc the atoms touch along the body diagonal: $4r=\sqrt3a$ .
$r=\frac{\sqrt3\times4.29}4\approx1.86\text{ Å}.$

JEE Main 2015 · 4 Apr · Shift 1, Chemistry question 32