Question
Chemistry Question on The solid state
What is the edge length of the unit cell of a body-centred cubic crystal of an element whose atomic radius is 75 pm?
A
170 pm
B
175 pm
C
178 pm
D
173.2 pm
Answer
173.2 pm
Explanation
Solution
For a body-centered cubic lattice, the relationship between the edge length a and the radius r is as follows: a =43 r.
By substituting the given value into the above equation: pm a =43×75=173.2pm.
Therefore, the length of the edge of the unit cell is 173.2 pm.
The correct answer is option (D): 173.2 pm