# What is a redox reaction?

A redox reaction occurs when one substance involved in the reaction is reduced, and another substance is oxidized.

Thanks, but that doesn't help me too much!

Q: What does it mean for something to be reduced?
A: That means the charge of that substance has been reduced due to the addition of negatively charged electrons.

Q: So what does it mean when something is oxidized?
A: When something is oxidized, it means it has lost electrons and gains a positive charge (subtraction of a negative)

Q: What is an example of a redox reaction?
A: Here is an example...

2$A g N {O}_{3}$ + Cu -> $C u {\left(N {O}_{3}\right)}_{2}$ + 2Ag

In this reaction the nitrate ion ($N {O}_{3}$) keeps the same -1 charge from the reactant side to the product side.

Cu begins with a charge of 0 as a reactant (pure elements are neutral) to a +2 charge when paired with 2 copies of the nitrate ion. This means the copper was oxidized.

The silver begins with a +1 charge (you know this because it's paired in a 1:1 ratio with the -1 nitrate) to having a charge of 0 when in its pure elemental form after the reaction. So the silver was reduced.

Here is a video discussing this topic:

Hope this helps!
Noel P.