---
title: "Redox: Oxidation and Reduction as Electron Transfer"
description: "Rewrite displacement and metal-with-acid reactions as electron transfer, where oxidation is loss of electrons and reduction is gain, and split a reaction into two half equations."
canonical: https://lightmysky.com/learn/science/redox-oxidation-and-reduction-as-electron-transfer-mt_NMTikR0FTM
source: https://lightmysky.com/learn/science/redox-oxidation-and-reduction-as-electron-transfer-mt_NMTikR0FTM.md
retrieved: 2026-09-12
---

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# Redox: Oxidation and Reduction as Electron Transfer

Rewrite displacement and metal-with-acid reactions as electron transfer, where oxidation is loss of electrons and reduction is gain, and split a reaction into two half equations.

Subject: Science · Area: Matter & Materials · Ages 14 to 16
Page: https://lightmysky.com/learn/science/redox-oxidation-and-reduction-as-electron-transfer-mt_NMTikR0FTM

## Ready when they can

- Names which species is oxidised and which is reduced in a displacement reaction
- Writes the two ionic half equations with electrons balanced
- Explains the reactivity series as an order of how readily a metal gives up electrons
- Relates the older gain-of-oxygen definition to the electron definition using the same reaction

## Lesson: Follow the electrons

Oxidation means losing electrons and reduction means gaining them. Remember it as OIL RIG: oxidation is loss, reduction is gain. The two always pair up, because every electron lost by one species is gained by another.

**Example.** Drop zinc into copper sulfate solution and blue fades as copper coats the zinc. Zinc gives away two electrons, so zinc is oxidised. Copper ions take those electrons, so copper is reduced.

Split the reaction to see the swap. The oxidation half is zinc becoming zinc ions plus two electrons, and the reduction half is copper ions plus two electrons becoming copper. Balance atoms first, then balance charges with electrons.

**Tip.** Read the reactivity series as a giving order. A metal higher up gives up electrons more readily and pushes a lower metal out of its solution. The older oxygen definition still works: gaining oxygen is oxidation, and losing it is reduction.

**Recap.** Losers oxidise, gainers reduce, and half equations show the electron trade.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Ionic Bonding: Electron Transfer and Charged Lattices](https://lightmysky.com/learn/science/ionic-bonding-electron-transfer-and-charged-lattices-mt_sf24C4YLtN)
- [Types of Chemical Reaction](https://lightmysky.com/learn/science/types-of-chemical-reaction-mt_v0K6GRi4ZL)
- [The Reactivity Series](https://lightmysky.com/learn/science/the-reactivity-series-mt_zsYW61cn_q)

## Opens up

- [Oxidation Numbers and Balancing Redox Equations](https://lightmysky.com/learn/science/oxidation-numbers-and-balancing-redox-equations-mt_4xuYKYgUex)
- [Electrolysis: Half Equations at the Electrodes](https://lightmysky.com/learn/science/electrolysis-half-equations-at-the-electrodes-mt_6FvxaD8wTY)
- [Extracting Metals: Reduction with Carbon and Choosing a Method](https://lightmysky.com/learn/science/extracting-metals-reduction-with-carbon-and-choosing-a-method-mt_LRAEJa8OLr)
- [Strong and Weak Acids and the pH Scale](https://lightmysky.com/learn/science/strong-and-weak-acids-and-the-ph-scale-mt_Y4nSn5XH56)