Copper has face centered cubic (fcc) lattice with interatomic spacing equal to 2.54 Å. The value of lattice constant for this lattice is
Answer & explanation
Correct answer: option 2
Given interatomic spacing = 2r = 2.54 Å
$4r=\sqrt{2} a$, where a is lattice constant $2r=\frac{\sqrt{2}a}{2}=\frac{a}{\sqrt{2}}$
$a=2r\sqrt{2}= (2.54Å)(1.414) = 3.59Å$