When a compound is oxidized it one or more electrons; whereas when a compound is reduced it one or more electrons?

"When a compound is oxidized it loses one or more electrons; whereas when a compound is reduced it gains one or more electrons"

Explanation:

Oxidation-reduction reactions or redox reactions are those in which an electron transfer occurs between the reagents. An electron transfer implies that there is a change in the number of oxidation between the reagents and the products.  Remember that the oxidation number is defined as the charge that an atom would have if the electrons in the bond were assigned to the most electronegative element.

The gain of electrons is called reduction and the loss of electrons oxidation. That is to say, there is oxidation whenever an atom or group of atoms loses electrons (or increases its positive charges) and in the reduction an atom or group of atoms gains electrons, increasing its negative charges or decreasing the positive ones.

The species that supplies electrons is the reducing agent (that is, it is that species that oxidizes, yielding electrons and increasing its positive charge, or decreasing the negative one causing the reduction of the other species) and the one that gains them is the oxidizing agent ( that is, it is that species that is reduced, capturing electrons and increasing its negative charge, or decreasing its positive charge, causing oxidation of the other species).

Electron donors are called reducers; Electron acceptors are called oxidants.

This is why these reactions are called oxidation-reduction reactions. In them there is a transfer of electrons from the oxidizing substance to the one that is reduced.

A redox system or redox pair is formed by an oxidant or its conjugate reducer. For a redox reaction to take place, two semi-reactions or redox systems are needed. Oxidation and reduction take place at the same time, this is at the same time. It cannot happen without the other.

Taking into account all the above definitions, it is possible to say that "When a compound is oxidized it loses one or more electrons; whereas when a compound is reduced it gains one or more electrons"