Answer:
coordination number
Explanation:
Coordination number -
In a crystal lattice , the number of atoms that are surrounded to a particular atom , is referred to as the coordination number of the crystal.
In the field of crystallography and chemistry , it is also called the ligancy.
In coordination chemistry , the number of ligands attached to the central metal atom is also known as the coordination number of the coordination compound.
Hence, from the given statement of the question,
The correct term is coordination number.
