Answer
a) Oxidation is the loss of electrons, while reduction is the gain of them.
b) The number of electrons lost is equal to the number of electrons gained; this is the conservation of energy.
c) Yes, by definition, the electrochemical processes involve transfer of electrons. (oxidation and reduction)
Work Step by Step
a) OIL RIG is an acronym that can be used to remember which is which. It stands for Oxidation is losing electrons, reduction is gaining electrons.
b) The number of electrons stays the same in the circuit. For example, in the galvanic cell of zinc and copper, zinc loses two electrons while copper gains two.
c) Electrochemical reactions are called REDOX, which is reduction-oxidation reactions. By definition, it always involves electrons transfer.