Copper crystallises in face centred cubic lattice with a edge length of 361pm. What is the radius of copper atom in pm?

As given that copper crystallizes in FCC lattice (Face centered cubic). In FCC, atoms are present on the corners of the cubic unit cell as well as on the face centers of each face. The atoms on the face diagonal will be touching each other. Let, the radius of the atom be r and edge length of the cube be a. Face diagonal of cube= 2a 2 2 2 361 4 2 2 2 2 r r r a a a r = 128pm Hence the correct answer is option (a) Solid state 12