What is electrochemistry ?

Electrochemistry is the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to another in a reaction known as an oxidation-reduction  ("redox") reaction.

A redox reaction is a reaction that involves a change in oxidation state of one or more elements. When a substance loses an electron, its oxidation state increases; thus, it is oxidized. When a substance gains an electron, its oxidation state decreases, thus being reduced. For example, for the redox reaction 

can be rewritten as follows:

Oxidation: H2→2H++2e−

Reduction: F2+2e−→2F−

Overall Reaction : H2+F2→2H++2F−

Oxidation is the loss of electrons, whereas reduction refers to the acquisition of electrons, as illustrated in the respective reactions above. The species being oxidized is also known as the reducing agent or reductant, and the species being reduced is called the oxidizing agent or oxidant. In this case, H2 is being oxidized (and is the reducing agent), while F2 is being reduced (and is the oxidizing agent).