Chemistry A-Level
Oxidation Number
What Oxidation Number means in Chemistry A-Level, as defined for Pearson Edexcel.
Definition of Oxidation Number
A number assigned to an element in chemical combination that represents the number of electrons lost or gained by an atom of that element in the compound.
Topics that use Oxidation Number
- Topic 1: Atomic Structure and the Periodic Table (Pearson Edexcel A-Level)
- Topic 2: Bonding and Structure (Pearson Edexcel A-Level)
Related terms
Using Oxidation Number in the exam
Definition questions usually carry one or two marks, and examiners look for the precise wording. Write the definition from memory, check it against the version above, and then use the term in a longer answer on the same topic so it sticks.
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