Electroneutrality
Summary: The state of having no net electric charge, because positive and negative charges balance exactly. Tags: igcse chemistry keyword Created: 2026-08-06
Electroneutrality is the condition of having no overall (net) electric charge. In a neutral atom, the number of protons (positive charges) equals the number of electrons (negative charges), so the charges cancel out and the atom is electrically neutral. If an atom gains or loses electrons, this balance is upset and it becomes a charged ion.
The same principle applies to compounds: in any neutral compound, the total positive charge equals the total negative charge. For example, in sodium chloride (NaCl) the +1 charge of the Na⁺ ion is balanced by the −1 charge of the Cl⁻ ion; in magnesium oxide (MgO) the +2 charge of Mg²⁺ balances the −2 charge of O²⁻. The IGCSE exam point is using electroneutrality to deduce ionic formulae — the formula of an ionic compound must be the simplest whole-number ratio in which positive and negative charges balance.
Sources
- Cambridge IGCSE Chemistry 0620 Syllabus (2023-2025), Cambridge Assessment International Education
Common Misconceptions
| Misconception | Reality |
|---|---|
| A neutral atom has equal numbers of protons and neutrons | A neutral atom has equal numbers of protons and electrons; neutrons are neutral particles and don’t affect charge |
| The formula of an ionic compound just joins the symbols | The formula is the ratio that balances total positive and negative charges (e.g. MgCl₂ because Mg²⁺ needs two Cl⁻) |
| An atom becomes neutral when it gains charge | Gaining or losing electrons makes an atom charged (an ion); neutrality means equal protons and electrons |