Chemistry: coordination compound

Tutoring chemistry, you encounter coordination compounds. The tutor begins about them.

A coordination compound is a species consisting of a central metal surrounded by nonmetals. The surrounding nonmetals are often the same, and can be ions, polyatomic ions, or simply molecules such as ammonia or water. Typically the attraction that forms the coordination compound is that the central atom acts as a Lewis acid while the surrounding nonmetals act as Lewis bases. The surrounding nonmetals are also known as ligands.

Source:

chem.libretexts.org