The central atom is the atom in a molecule or ion to which the surrounding atoms and lone pairs are attached. It is usually the least electronegative atom and the one that forms the most bonds. Identifying the central atom is the first step in predicting molecular shape with VSEPR theory.

中心原子是分子或离子中与周围原子和孤对相连的原子。它通常是电负性最小、成键最多的原子。确定中心原子是用价层电子对互斥理论预测分子形状的第一步。