Oxidation and reduction in terms of electrons (HT only): Oxidation is the loss of electrons and reduction is the gain of electrons.

Q: How do I revise Oxidation and reduction in terms of electrons (HT only): Oxidation is the loss of electrons and reduction is the gain of electrons. for GCSE?

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Q: Is this Oxidation and reduction in terms of electrons (HT only): Oxidation is the loss of electrons and reduction is the gain of electrons. guide aligned to the AQA specification?

Yes. This guide is linked to the Oxidation and reduction in terms of electrons (HT only): Oxidation is the loss of electrons and reduction is the gain of electrons. topic in the AQA GCSE specification.

In terms of electrons, oxidation is loss of electrons and reduction is gain of electrons.

Study notes

From the checked teaching notes for this specification point.

The idea

What earns the marks

State that oxidation is loss of electrons and reduction is gain of electrons.
Identify electron loss or gain by comparing the charge of a species before and after reaction.
Apply the definition to ionic equations, such as displacement reactions and electrolysis.
Use oxidation states or ion charges to confirm which species is oxidised or reduced.

Common mistakes and how to put them right

Reversing the definitions: remember 'OIL RIG' — Oxidation Is Loss, Reduction Is Gain of electrons.
Confusing gain of electrons with gain of oxygen.
Put it right: In electron terms, reduction is gain of electrons, not oxygen.
Forgetting to balance charge when writing half-equations.
Put it right: Ensure the number of electrons lost equals the number gained overall.

Exam tips

Write the relevant half-equations to show electron loss or gain clearly.
Check the charge on each side of the equation to confirm whether electrons are lost or gained.

Try the lesson

The start of the Oxidation and reduction in terms of electrons (HT only): Oxidation is the loss of electrons and reduction is the gain of electrons. lesson, made from checked teaching notes for this specification point.

Have a go first

In terms of electrons, what happens to a substance when it is oxidised?

Tip: press 1 to 4 to choose

Listen

In terms of electrons, oxidation is loss of electrons and reduction is gain of electrons. This applies to reactions involving ions, such as displacement and electrolysis. For example, in Zn + Cu²⁺ → Zn²⁺ + Cu, zinc atoms lose electrons to form Zn²⁺, so zinc is oxidised, while Cu²⁺ ions gain electrons to form Cu, so copper(II) ions are reduced. To identify which species is oxidised or reduced, compare the charge and formula of each species before and after reaction. An increase in positive charge or loss of negative charge indicates electron loss (oxidation); a decrease in positive charge or gain of negative charge indicates electron gain (reduction). This electron-transfer definition is required for higher tier and supports understanding of redox in electrolysis and metal displacement. A strong answer earns marks for these points. State that oxidation is loss of electrons and reduction is gain of electrons. Identify electron loss or gain by comparing the charge of a species before and after reaction. Apply the definition to ionic equations, such as displacement reactions and electrolysis. Use oxidation states or ion charges to confirm which species is oxidised or reduced. Exam tip: Write the relevant half-equations to show electron loss or gain clearly.

See it

A top-down flowchart. At the top, two separate branches: 'Oxidation' leads to 'Loss of electrons', and 'Reduction' leads to 'Gain of electrons'. Below, the example 'Zn + Cu²⁺ → Zn²⁺ + Cu' branches into two paths. The first path goes to 'Zinc atoms lose electrons to form Zn²⁺', which leads to 'Zinc is oxidised'. The second path goes to 'Cu²⁺ ions gain electrons to form Cu', which leads to 'Copper(II) ions are reduced'. — It shows that oxidation is the loss of electrons and reduction is the gain of electrons, and applies this to the example Zn + Cu²⁺ → Zn²⁺ + Cu.

Label the diagram

Some boxes have lost their names. Pick the right name for each number.

The diagram again, with 3 boxes numbered instead of named. A top-down flowchart. At the top, two separate branches: 'Oxidation' leads to 'Loss of electrons', and 'Reduction' leads to 'Gain of electrons'. Below, the example 'Zn + Cu²⁺ → Zn²⁺ + Cu' branches into two paths. The first path goes to 'Zinc atoms lose electrons to form Zn²⁺', which leads to 'Zinc is oxidised'. The second path goes to 'Cu²⁺ ions gain electrons to form Cu', which leads to 'Copper(II) ions are reduced'.

1Box 1
2Box 2
3Box 3

0 of 3 labelled

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