Traditional chemistry starts with the study of elementary particles, atoms, molecules, substances, metals, crystals and other aggregates of matter. in
solid, liquid, and gasstates, whether in isolation or combination. The interactions, reactions and
transformations that are studied in chemistry are usually a result of
interaction between atoms, leading to rearrangements in the chemical bonds which hold atoms together. Such
behaviors are studied in a chemistry laboratory.
The chemistry laboratory
stereotypically uses various forms of laboratory
glassware, but glassware is not central to chemistry, and a great deal of
experimental (as well as applied/industrial chemistry) is done without it.
A chemical
reaction is a transformation of
some substances into one or more other substances. The basis of such a chemical
transformation is the rearrangement of electrons in the chemical bonds between atoms. It can be symbolically
depicted through a chemical
equation, which usually involves atoms as subjects. The number of atoms on the
left and the right in the equation for a chemical transformation is equal (when
unequal, the transformation by definition is not chemical, but rather a nuclear reaction or radioactive
decay). The nature of chemical reactions a substance may undergo and the energy
changes that may accompany it are constrained by certain basic rules, known as
chemical laws.
Energy and entropy considerations are invariably
important in almost all chemical studies. Chemical substances are classified in
terms of their structure, phase
as well as their chemical
compositions. They can be analyzed using the tools of chemical analysis, e.g.spectroscopy and chromatography. Scientists engaged in chemical research are known as chemists. Most chemists specialize in one or
more sub-disciplines.
It is a concept related to the ability of atoms of various
substances to lose or gain electrons. Substances that have the ability to
oxidize other substances are said to be oxidative and are known as oxidizing agents, oxidants or
oxidizers. An oxidant removes electrons from another substance. Similarly,
substances that have the ability to reduce other substances are said to be
reductive and are known asreducing agents, reductants, or reducers.
A reductant transfers electrons to
another substance, and is thus oxidized itself. And because it
"donates" electrons it is also called an electron donor. Oxidation
and reduction properly refer to a change in oxidation number—the actual transfer
of electrons may never occur. Thus, oxidation is better defined as an increase
in oxidation number, and
reduction as a decrease in oxidation number.
