Question

what will be the atomic radius of copper, if the distance between two adjacent copper atoms in metallic copper is 256 pm?
a 512 pm
b 128 pm
c 140 pm
d 256 pm

Explanation:

Step1: Recall atomic - radius concept

The distance between two adjacent atoms in a metallic structure is equal to 2 times the atomic radius of the atom. Let the atomic radius be $r$ and the distance between two adjacent atoms be $d$. Then $d = 2r$.

Step2: Solve for atomic radius

Given $d=256$ pm. Rearranging the formula $d = 2r$ to solve for $r$, we get $r=\frac{d}{2}$. Substituting $d = 256$ pm into the formula, we have $r=\frac{256}{2}=128$ pm.

Answer:

B. 128 pm