Question

Sodium metal crystallizes in a body-centered cubic lattice with a unit cell edge of $4.29$ $\mathring{A}$. The radius (in $\mathring{A}$) of sodium atom is approximately:

• A. $1.86$
• B. $3.22$
• C. $5.72$
• D. $0.93$

Answer 1

The correct option is A $1.86$

In bcc structure, the radius of sodium atom is $0.433a=0.433\times 4.29\mathring{A}=1.86\mathring{A}$