What is meant by the term "coordination number"?
b. What is the coordination number of atoms:
i. in a cubic-packed structure?
ii. In a body-centreds structure?

Explanation

The number of nearest neighbouring particles of a particle is defined as the co-ordination number .
OR
The number of nearest oppositely charged ions surrounding a particular ion is called as co-ordination number .
E.g. : Co-ordination no. of `Na^(+)` in NaCl lattice is 6 .