Electron Transfer
Summary: The movement of electrons from one atom to another, forming oppositely charged ions. Tags: igcse chemistry keyword Created: 2026-08-06
Electron transfer is the process by which electrons move from one atom to another during the formation of ionic bonds. In ionic bonding, a metal atom transfers one or more of its outer-shell electrons to a non-metal atom. The metal atom, having lost electrons, becomes a positive ion (cation), while the non-metal atom, having gained electrons, becomes a negative ion (anion). The oppositely charged ions are then held together by strong electrostatic attraction — the ionic bond.
A classic IGCSE example is sodium chloride: the sodium atom (2,8,1) transfers its single outer electron to the chlorine atom (2,8,7), forming Na⁺ (2,8) and Cl⁻ (2,8,8). Both ions now have stable noble-gas electron configurations. The key exam point is being able to describe electron transfer using dot-and-cross diagrams, showing the movement of electrons from metal atoms to non-metal atoms, and to note that metals lose electrons (becoming positive) while non-metals gain electrons (becoming negative).
Sources
- Cambridge IGCSE Chemistry 0620 Syllabus (2023-2025), Cambridge Assessment International Education
Common Misconceptions
| Misconception | Reality |
|---|---|
| Non-metals can lose electrons to form positive ions in ionic bonds | In ionic bonding non-metals gain electrons to form negative ions; metals lose electrons to form positive ions |
| Electron transfer creates a covalent bond | Transfer of electrons forms ionic bonds; covalent bonds involve sharing rather than transferring |
| The transferred electrons are shared equally afterwards | The electron is lost entirely by the metal and gained entirely by the non-metal, creating full opposite charges |