Does anyone know how to determine if a reaction is a redox or not? 2Ca+O2→2CaO2 is the reaction. I've already made it a balanced equation, I just need to determine if its a redox or not.
Thank you!

The reaction is included in a redox reaction

Further explanation:

Given

Reaction

2 Ca + O₂ → 2 CaO

Required

a redox reaction

Solution

Redox reactions are reactions where there is a change in oxidation number

Oxidation is an increase/increase in oxidation number, while reduction is a decrease/decrease in oxidation number.

Reducing agents are substances that experience oxidation  and oxidizing agent are substances that experience reduction

in the above reaction is included in a redox reaction because there is a change in oxidation number

Ca⇒Ca²⁺+ 2e⁻(for balanced equation : 2Ca⇒2Ca²⁺+4e⁻)

Oxidation ( 0 to +2)

O₂+2e⁻⇒O²⁻(for balanced equation : O₂+4e⁻⇒2O²⁻)

Reduction (0 to -2)