Question

Metallic gold crystallizes in fcc lattice. The length of the cubic unit cell is $4.07\stackrel{o}{A}$. What is the closest distance between gold atoms?

• A. $2.03$
• B. $2.66$
• C. $2.88$
• D. $1.73$

Answer 1

The correct option is A $2.03$

Closest distance in FCC lattice is $\frac{a}{2}$ where, ${}^{\prime }{a}^{\prime }$ is length of cubic. Therefore, closest distance between gold atoms

$=\frac{4.07}{2}$

$=2.035\approx 2.03\mathring{A}$