In a redox reaction, why does an element’s oxidation number decrease?

Question

A.
An element’s oxidation number decreases because it gained electrons.
B.
An element’s oxidation number decreases because it exchanged electrons.
C.
An element’s oxidation number decreases because it lost electrons.
D.
An element’s oxidation number decreases because it was heated.

Answer 1

The correct answer is:

A. An element’s oxidation number decreases because it gained electrons.

In redox reactions, a decrease in oxidation number indicates that an element has been reduced, which is associated with the gain of electrons.