---
title: "Central Atom — AP Chem Definition & Lewis Structure Guide"
description: "The central atom is the atom bonded to two or more others in a molecule. Picking it correctly is step one of every Lewis diagram, VSEPR shape, and formal charge problem in AP Chem."
canonical: "https://fiveable.me/ap-chem/key-terms/central-atom"
type: "key-term"
subject: "AP Chemistry"
---

# Central Atom — AP Chem Definition & Lewis Structure Guide

## Definition

In molecular geometry, central atom is an atom in a molecule or ion that has bonds with two or more other atoms.

## Related Study Guides

- [2.5 Lewis Diagrams](/ap-chem/unit-2/lewis-diagrams/study-guide/KjqTRYr5TVr2C3Be3u0J)
- [2.6 Resonance and Formal Charge](/ap-chem/unit-2/resonance-formal-charge/study-guide/rxtiCdBiDF6V9V7S2UEi)

## Review

### Related Terms

- [Lone Pair Electrons](/ap-chem/key-terms/lone-pair-electrons): These are pairs of valence electrons that are not used in bonding but belong exclusively to one atom.
- [Octet Rule](/ap-chem/key-terms/octet-rule): A rule stating that atoms lose, gain, or share electrons so as to have eight valence electrons.
- VSEPR Theory (Valence Shell Electron Pair Repulsion): A model used to predict molecular shapes based on minimizing repulsion between electron pairs around a central atom.