Photochemistry:
Photochemistry is the category of chemistry treated with the chemical effects of light. Commonly, this phase is used to describe a chemical reaction influenced by the absorption of ultraviolet (wavelength from 100 to 400 nm), visible light (400–750 nm), or infrared radiation (750–2500 nm).
Photochemistry is the primary process for all of the photobiology. When a molecule embodies a photon of light, its electronic formation changes, and it responds conversely with other molecules. The energy that is absorbed from light can happen in photochemical changes in the absorbing molecule, or in the next molecule (e.g., photosensitization). Every kind of molecule has a different choice for which of these different mechanisms it uses to discarded absorbed photon energy.
Photobiology:
Photobiology is mainly defined to cover all biological aspects including non-ionizing radiation. It is noticed that photobiological responses are the result of chemical and/or physical variations induced in biological systems by non-ionizing radiation.
Electrochemistry:
Electrochemistry is the knowledge of electricity and how it compares to chemical reactions. In electrochemistry, electricity can be produced by actions of electrons from one element to another in a reaction is called redox or oxidation-reduction reaction and it is the part of chemistry involved with the interrelation of electrical and chemical variations that are produced by the passage of current.
In electrochemistry two kinds of electrochemical cells: galvanic, also called Voltaic, and electrolytic. Galvanic cell defines its energy from automatic redox reactions, while electrolytic cells include non-spontaneous reactions and thus need an external electron source like a DC battery or an AC power source.
Electrochemistry has a number of various uses, particularly in industry. The sources of cells are used to create electrical batteries. In science and technology, a battery is a device that deposits chemical energy and makes it possible in an electrical form.