Coordination number

A coordination number refers to how many neighboring atoms or molecules are directly connected or "surround" a central atom within a structure, such as a crystal or molecule. Think of it like a friendship circle, where the number indicates how many friends (neighbors) are in close contact. In chemistry, this helps describe the arrangement and bonding of atoms in a material. For example, in table salt (sodium chloride), each sodium atom is surrounded by six chloride atoms, giving it a coordination number of 6. It’s a way to quantify the local environment around an atom.