Question

The coordination number of $\mathrm{Cu}$ is?

Answer 1

Co-ordination:

• The coordination number is basically known as the number of spheres that directly surround a single sphere in a given crystal.
• In other words, the number of nearest neighbors of any constituent particle present inside the crystal lattice is called as its coordination number.

The coordination number of $\mathrm{Cu}$:

• Copper usually forms FCC crystal lattice.
• The coordination number in a face-centered cubic close packing structure is known to be $12.$
• In this lattice structure, each sphere in a three-dimensional arrangement has been surrounded by 6 spheres in its own layer and three spheres each in the lower layer and upper layer.
• Thus, the nearest neighbors i.e coordination number for the FCC lattice for any sphere will be $12.$

Hence, the coordination number of $\mathrm{Cu}$ is $12.$