Oxidation is a reaction in which there is a (loss or gain) of electrons which results in a(n) (increase or decrease) in positive charge of the atom or ion.

Oxidation is a reaction in which there is a loss of electrons which results in an increase in positive charge of the atom or ion.

Explanation:

Oxidation is the process of loss one or more electrons.

Oxidation process includes loss of electrons to obtain a highly positively charged ions/atoms.

So, Oxidation is a reaction in which there is a loss of electrons which results in an increase in positive charge of the atom or ion.