The gain of electrons by an atom, ion, or molecule during a chemical reaction, resulting in a decrease in its oxidation state. Reduction is the other half of every redox reaction.
Definition
The gain of electrons by an atom, ion, or molecule during a chemical reaction, resulting in a decrease in its oxidation state.
💡 Intuition
Grabbing electrons. The charge gets 'reduced' (becomes more negative).
🎯 Core Idea
OIL RIG: Reduction Is Gain of electrons — always paired with oxidation in a redox reaction.
Example
🌟 Why It Matters
Reduction is the other half of every redox reaction. It enables metal extraction from ores (smelting iron from iron oxide), powers the cathode in every battery, and is essential for photosynthesis where CO₂ is reduced to glucose.
💭 Hint When Stuck
When identifying reduction in a reaction, track electron gain. First assign oxidation numbers to each atom before and after the reaction. Then find which atoms decreased in oxidation number — those were reduced. Finally, remember OIL RIG: Reduction Is Gain of electrons.
Formal View
Related Concepts
See Also
🚧 Common Stuck Point
Reduction and oxidation always happen together—electrons have to go somewhere.
⚠️ Common Mistakes
- Confusing reduction with oxidation — reduction is electron gain (oxidation number decreases), not electron loss
- Thinking the reduced species is the reducing agent — the substance that gets reduced is actually the oxidizing agent (it causes oxidation in the other species)
- Forgetting that reduction and oxidation always occur together — you cannot have one without the other in a chemical reaction
Frequently Asked Questions
What is Reduction in Chemistry?
The gain of electrons by an atom, ion, or molecule during a chemical reaction, resulting in a decrease in its oxidation state.
When do you use Reduction?
When identifying reduction in a reaction, track electron gain. First assign oxidation numbers to each atom before and after the reaction. Then find which atoms decreased in oxidation number — those were reduced. Finally, remember OIL RIG: Reduction Is Gain of electrons.
What do students usually get wrong about Reduction?
Reduction and oxidation always happen together—electrons have to go somewhere.
Visualization
StaticVisual representation of Reduction