What do you mean by the term coordination number? What is the coordination of each sphere in ccp structures

Explanation

### Step-by-Step Solution

1. **Definition of Coordination Number**:
- The coordination number is defined as the number of nearest neighboring spheres (or atoms) that are in contact with a given sphere (or atom) in a crystal structure. It indicates how many other particles are surrounding a central particle.

2. **Understanding CCP (Cubic Close Packing)**:
- In a cubic close packing (CCP) structure, the spheres are arranged in a way that maximizes the packing efficiency. This arrangement allows for a dense packing of spheres.

...