Question

The Cu metal crystallises into fcc lattice with a unit cell edge length of 361 pm. The radius of Cu atom is:

• A. 157 pm
• B. 181 pm
• C. 127 pm
• D. 108 pm

Answer 1

The Correct Option is C

The correct answer is Option 3: 127 pm

For a face-centered cubic (fcc) lattice, the relationship between the edge length (a) and the atomic radius (r) is given by:

4r = √2 * a

Where:

• r = atomic radius
• a = edge length

Given that the edge length (a) is 361 pm, we can calculate the radius (r):

4r = √2 * 361 pm

4r = 1.414 * 361 pm

4r = 510.454 pm

r = 510.454 pm / 4

r ≈ 127.6 pm

Therefore, the radius of the Cu atom is approximately 127 pm.

The correct answer is:

Option 1: 127 pm