'Chemistry' - Organic, Inorganic, biochemistry and physical is the study of interactions of chemical substances with one another and energy based on the structure of
atoms, molecules and other kinds of aggregrates
'Chemistry' (from
Egyptian ''kēme'' (chem), meaning
"earth"[1]) is the
science concerned with the composition, structure, and properties of
matter, as well as the changes it undergoes during
chemical reactions.
[2] Chemistry is a
physical science related to studies of various
atoms,
molecules,
crystals and other aggregrates of matter whether in isolation or combination. It also incorporates
energy and
entropy related studies to various
chemical substances.
There are several specialized disciplines within chemistry, traditionally grouped by the type of matter being studied or the kind of study, the main amongst them are:
★
Inorganic Chemistry, the study of
inorganic matter,
★
Organic Chemistry, the study of
organic matter,
★
Biochemistry, the study of
substances found in
biological organisms,
★
Physical chemistry, the
energy related studies of chemical systems at macro, molecular and submolecular scales.
Many more specialized disciplines have emerged (see
Subdisciplines and
applied fields).
Modern chemistry evolved out of
alchemy following the
chemical revolution (1773), through the reforms of many individuals, particularly French chemist
Antoine Lavoisier who, among others, is considered the "
father of modern chemistry". Other pioneers (fathers) of modern chemistry include:
Robert Boyle (1661),
John Dalton (1808),and
Jöns Jakob Berzelius (1828), while some consider
Geber (d. 815) to be the first chemist.
[3][4][5]
Overview
Chemistry is the scientific study of interaction of substances called
chemical substances
[6] that are constituted of
atoms or the subatomic components that make up atoms:
protons,
electrons and
neutrons.
[7] Atoms combine to produce
ions,
molecules or
crystals. Chemistry can be called "
the central science" because it connects the other
natural sciences, such as
astronomy,
physics,
material science,
biology, and
geology.
[8][9]
The genesis of chemistry can be traced to certain practices, known as
alchemy, which had been practiced for several
millennia in various parts of the world, particularly the middle east.
[10]
The structure of objects we commonly use and the properties of the matter we commonly interact with, are a consequence of the properties of chemical substances and their interactions. For example,
steel is
harder than iron because its atoms are bound together in a more rigid
crystalline lattice; wood burns or undergoes rapid
oxidation because it can react spontaneously with
oxygen in a
chemical reaction above a certain
temperature; sugar and salt dissolve in water because their molecular/ionic properties are such that dissolution is preferred under the ambient conditions.
The transformations that are studied in chemistry are a result of interaction either between different chemical substances or between
matter and
energy. Traditional chemistry involves study of
interactions between
substances in a chemistry
laboratory using various forms of
laboratory glassware.
Laboratory, Institute of Biochemistry, University of Cologne
A
chemical reaction is a transformation of some such substances into one or more other such substances.
[11] It can be symbolically depicted through a
chemical equation. The number of atoms on the left and the right in the equation for a chemical transformation is most often equal. 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 analysed using the tools of
chemical analysis, e.g.
spectroscopy and
chromatography.
Chemistry is an integral part of the
science curriculum both at the
high school as well as the early college level. At these levels, it is often called 'general chemistry' which is an introduction to a wide variety of fundamental concepts that enable the student to acquire tools and skills useful at the advanced levels, whereby chemistry is invariably studied in any of its various sub-disciplines.
Scientists, engaged in chemical
research are known as
chemists.
[12] Most chemists specialize in one or more sub-disciplines.
History
Main articles: History of chemistry
The genesis of chemistry can be traced to the widely observed phenomenon of
burning that led to
metallurgy- the art and science of processing ores to get metals (e.g.
metallurgy in ancient India). The greed for gold led to the discovery of the process for its purification, even though, the underlying principles were not well understood -- it was thought to be a transformation rather than purification. Many scholars in those days thought it reasonable to believe that there exist means for transforming cheaper (base) metals into gold. This gave way to alchemy, and the search for the
Philosopher's Stone, which was believed to bring about such a transformation by mere touch.
[13]
Some consider
medieval Muslims to be the earliest chemists, who introduced precise
observation and controlled
experimentation into the field, and discovered numerous
chemical substances.
[14] The most influential Muslim chemists were
Geber (d. 815),
al-Kindi (d. 873),
al-Razi (d. 925), and
al-Biruni (d. 1048).
[15] The works of Geber became more widely known in Europe through
Latin translations by a
pseudo-Geber in 14th century
Spain, who also wrote some of his own books under the pen name "Geber". The contribution of
Indian alchemists and metallurgists in the development of chemistry was also quite significant.
[16]
The emergence of chemistry in Europe was primarily due to the recurrent incidence of the
plague and blights there during the so called
Dark Ages. This gave rise to a need for medicines. It was thought that there exists a universal medicine called the
Elixir of Life that can cure all diseases, but like the Philosopher's Stone, it was never found.
For some practitioners alchemy was an intellectual pursuit, over time, they got better at it.
Paracelsus (1493-1541), for example, rejected the 4-elemental theory and with only a vague understanding of his chemicals and medicines, formed a hybrid of alchemy and science in what was to be called ''
iatrochemistry''. Similarly, the influences of philosophers such as
Sir Francis Bacon (1561-1626) and
René Descartes (1596-1650), who demanded more rigor in mathematics and in removing bias from scientific observations, led to a
scientific revolution. In chemistry, this began with
Robert Boyle (1627-1691), who discovered gases, and came up with equations that were known as
Boyle's Law.
[17] Chemistry indeed came of age when
Antoine Lavoisier (1743-1794), developed the theory of
Conservation of mass in 1783; and the development of the
Atomic Theory by
John Dalton around 1800. The Law of Conservation of Mass resulted in the reformulation of chemistry based on this law and the oxygen theory of combustion, which was largely based on the work of Lavoisier. Lavoisier's fundamental contributions to chemistry were a result of a conscious effort to fit all experiments into the framework of a single theory. He established the consistent use of the chemical balance, used oxygen to overthrow the
phlogiston theory, and developed a new system of chemical nomenclature and made contibution to the modern metric system. Lavoisier also worked to translate the archaic and technical language of chemistry into something that could be easily understood by the largely uneducated masses, leading to an increased public interest in chemistry. All these advances in chemistry led to what is usually called the
chemical revolution. The contributions of Lavoisier led to what is now called modern chemistry - the chemistry that is studied in educational institutions all over the world. It is because of these and other contribtuions that Antoine Lavoisier is often celebrated as the "Father of Modern Chemistry". The later discovery of
Friedrich Wöhler that many natural substances, the
Organic compounds, can indeed be synthesized in a chemistry
laboratory also helped the modern chemistry to mature from its infancy.
The
discoveries of the chemical elements has a long history from the days of alchemy and culminating in the creation of the
periodic table of the chemical elements by
Dmitri Mendeleev (1834-1907)
[18] and later discoveries of some
synthetic elements.
Etymology
Main articles: Chemistry (etymology)
The word ''chemistry'' comes from the earlier study of alchemy, which is basically the quest to make gold from earthen starting materials.
[19] As to the origin of the word "alchemy" the question is a debatable one; it certainly can be traced back to the Greeks, and some, following E. Wallis Budge, have also asserted
Egyptian origins. Alchemy, generally, derives from the old French ''alkemie'' from the Arabic ''al-kimia'' - "the art of transformation". The Arabs borrowed the word "kimia" from the Greeks when they conquered
Alexandria in the year 642 AD. A tentative outline is as follows:
#Egyptian alchemy [5,000 BCE – 400 BCE], formulate early "element" theories such as the
Ogdoad.
#Greek alchemy [332 BCE – 642 CE], the Greek king
Alexander the Great conquers Egypt and founds Alexandria, having the world's largest library, where scholars and "wise" men gather to study.
#
Arabian alchemy [642 CE – 1200], the Arabs take over Alexandria;
Jabir is the main chemist
#European alchemy [1300 – present],
Pseudo-Geber builds on Arabic chemistry
#Chemistry [1661],
Boyle writes his classic chemistry text ''The Sceptical Chymist''
#Chemistry [1787],
Lavoisier writes his classic ''Elements of Chemistry''
#Chemistry [1803],
Dalton publishes his ''Atomic Theory''
Thus, an alchemist was called a 'chemist' in popular speech, and later the suffix "-ry" was added to this to describe the art of the chemist as "chemistry".
Definitions
In retrospect, the definition of chemistry seems to invariably change per decade, as new discoveries and theories add to the functionality of the science. Shown below, for example, are some of the standard definitions used by various noted chemists:
★ 'Alchemy' (330) – the study of the composition of waters, movement, growth, embodying and disembodying, drawing the spirits from bodies and bonding the spirits within bodies (
Zosimos).
[20]
★ 'Chymistry' (1661) – the subject of the material principles of mixt bodies (
Boyle).
[21]
★ 'Chymistry' (1663) – a scientific art, by which one learns to dissolve bodies, and draw from them the different substances on their composition, and how to unite them again, and exalt them to an higher perfection (
Glaser).
[22]
★ 'Chemistry' (1730) – the art of resolving mixt, compound, or aggregate bodies into their principles; and of composing such bodies from those principles (
Stahl).
[23]
★ 'Chemistry' (1837) – the science concerned with the laws and effects of molecular forces (
Dumas).
[24]
★ 'Chemistry' (1947) – the science of substances: their structure, their properties, and the reactions that change them into other substances (
Pauling).
[25]
★ 'Chemistry' (1998) – the study of matter and the changes it undergoes (
Chang).
[26]
Basic concepts
Several
concepts are essential for the study of chemistry, some of them are:
[27]
Atom
Main articles: Atom
An ''atom'' is the basic unit of an element. It is a collection of matter consisting of a positively charged core (the
atomic nucleus) which contains
protons and
neutrons, and which maintains a number of
electrons to balance the positive charge in the nucleus. Atom is also the smallest entity that can be envisaged to retain some of the
chemical properties of the element, viz.
Electronegativity,
Ionization potential, Preferred
oxidation state(s),
Coordination number, Preferred types of
bonds to form e.g.,
metallic,
ionic,
covalent.
Element
Main articles: Chemical element
The concept of ''chemical element'' is related to that of chemical substance. A chemical element is characterized by a particular number of
protons in the
nuclei of its atoms. This number is known as the
atomic number of the element. For example, all atoms with 6 protons in their nuclei are atoms of the chemical element
carbon, and all atoms with 92 protons in their nuclei are atoms of the element
uranium. However, several
isotopes of an element, that differ from one another in the number of neutrons present in the nucleus, may exist.
The most convenient presentation of the chemical elements is in the
periodic table of the chemical elements, which groups elements by atomic number. Due to its ingenious arrangement,
groups, or columns, and
periods, or rows, of elements in the table either share several chemical properties, or follow a certain trend in characteristics such as
atomic radius,
electronegativity, etc. Lists of the elements
by name,
by symbol, and by
atomic number are also available.
Compound
Main articles: Chemical compound
A ''compound'' is a substance with a ''particular ratio'' of atoms of particular
chemical elements which determines its composition, and a particular
organization which determines chemical properties. For example,
water is a compound containing
hydrogen and
oxygen in the ratio of two to one, with the oxygen between the hydrogens, and an angle of 104.5° between them. Compounds are formed and interconverted by
chemical reactions.
Substance
Main articles: Chemical substance
A chemical substance is a kind of matter with a definite
composition and set of
properties. Strictly speaking, a mixture of compounds, elements or compounds and elements is not a chemical substance, but it may be called a chemical. Most of the substances we encounter in our daily life are some kind of mixture, e.g.
air,
alloys,
biomass etc.
Nomenclature of substances is a critical part of the language of chemistry. Generally it refers to a system for naming
chemical compounds. Earlier in the history of chemistry substances were given name by their discoverer, which often led to some confusion and difficulty. However, today the IUPAC system of chemical nomenclature allows chemists to specify by name specific compounds amongst the infinite variety of possible chemicals. The standard nomenclature of chemical substances is set by the
International Union of Pure and Applied Chemistry (IUPAC). There are well-defined systems in place for naming chemical species.
Organic compounds are named according to the
organic nomenclature system.
[28] Inorganic compounds are named according to the
inorganic nomenclature system.
[29] In addition the
Chemical Abstracts Service has devised a method to index chemical substance. In this scheme each chemical substance is identifiable by a numeric number known as
CAS registry number.
Molecule
Main articles: Molecule
A ''molecule'' is the smallest indivisible portion, beside an atom, of a pure
chemical substance that has its unique set of chemical properties, that is, its potential to undergo a certain
set of chemical reactions with other substances. Molecules can exist as electrically neutral units unlike
ions. Molecules are typically a set of atoms bound together by
covalent bonds, such that the structure is electrically neutral and all valence electrons are paired with other electrons either in bonds or in
lone pairs.
A molecular structure depicts the bonds and relative positions of atoms in a molecule such as that in
Paclitaxel shown here
One of the main characteristic of a molecule is its geometry often called its
structure. While the structure of diatomic, triatomic or tetra atomic molecules may be trivial, (linear, angular pyramidal etc.) the structure of polyatomic molecules, that are constituted of more than six atoms (of several elements) can be crucial for its chemical nature.
Mole
A mole is the amount of a
substance that contains as many elementary entities (atoms, molecules or ions) as there are atoms in 0.012
kilogram (or 12
grams) of
carbon-12, where the carbon-12 atoms are unbound, at rest and in their
ground state.
[30] The number of atoms in 0.012 kilogram of carbon-12 is known as the
Avogadro constant, and is determined empirically. The currently accepted value is 6.02214179(30) mol
-1 (2007
CODATA). It is much like the term "a
dozen" in that it is an absolute number (having no units) and can describe any type of elementary object, although the mole's use is usually limited to measurement of
subatomic,
atomic, and
molecular structures.
The number of moles of a substance in one liter of a
solution is known as its
molarity. Molarity is the common unit used to express the
concentration of a solution in
physical chemistry.
Ions and Salts
Main articles: Ion
An ''ion'' is a charged species, or an atom or a molecule that has lost or gained one or more electrons. Positively charged
cations (e.g.
sodium cation Na
+) and negatively charged
anions (e.g.
chloride Cl
−) can form a crystalline lattice of neutral
salts (e.g.
sodium chloride NaCl). Examples of
polyatomic ions that do not split up during
acid-base reactions are
hydroxide (OH
−) and
phosphate (PO
43−).
Ions in the gaseous phase is often known as
plasma.
Phase
Main articles: Phase (matter)
In addition to the specific chemical properties that distinguish different chemical classifications chemicals can exist in several phases. For the most part, the chemical classifications are independent of these bulk phase classifications; however, some more exotic phases are incompatible with certain chemical properties. A ''phase'' is a
set of states of a chemical system that have similar bulk structural properties, over a range of conditions, such as
pressure or
temperature. Physical properties, such as
density and
refractive index tend to fall within values characteristic of the phase. The phase of matter is defined by the ''
phase transition'', which is when energy put into or taken out of the system goes into rearranging the structure of the system, instead of changing the bulk conditions.
Sometimes the distinction between phases can be continuous instead of having a discrete boundary, in this case the matter is considered to be in a
supercritical state. When three states meet based on the conditions, it is known as a
triple point and since this is invariant, it is a convenient way to define a set of conditions.
The most familiar examples of phases are
solids,
liquids, and
gases. Many substances exhibit multiple solid phases. For example, there are three phases of solid
iron (alpha, gamma, and delta) that vary based on temperature and pressure. A principle difference between solid phases is the
crystal structure, or arrangement, of the atoms. Less familiar phases include
plasmas,
Bose-Einstein condensates and
fermionic condensates and the
paramagnetic and
ferromagnetic phases of
magnetic materials. While most familiar phases deal with three-dimensional systems, it is also possible to define analogs in two-dimensional systems, which has received attention for its relevance to systems in
biology.
Chemical bond
Main articles: Chemical bond
A ''chemical bond'' is a concept for understanding how atoms stick together in molecules. It may be visualized as the
multipole balance between the positive charges in the nuclei and the negative charges oscillating about them.
[31] More than simple attraction and repulsion, the energies and distributions characterize the availability of an electron to bond to another atom. These potentials create the
interactions which holds together
atoms in
molecules or
crystals. In many simple compounds,
Valence Bond Theory, the Valence Shell Electron Pair Repulsion model (
VSEPR), and the concept of
oxidation number can be used to predict molecular structure and composition. Similarly, theories from
classical physics can be used to predict many ionic structures. With more complicated compounds, such as
metal complexes, valence bond theory fails and alternative approaches, primarily based on principles of
quantum chemistry such as the
molecular orbital theory, are necessary. See diagram on electronic orbitals.
Chemical reaction
Main articles: Chemical reaction
''Chemical reaction'' is a concept related to the transformation of a
chemical substance through its interaction with another, or as a result of its interaction with some
form of energy. A chemical reaction may occur naturally or carried out in a laboratory by chemists in specially designed vessels which are often
laboratory glassware. It can result in the formation or
dissociation of molecules, that is, molecules breaking apart to form two or more smaller molecules, or rearrangement of
atoms within or across molecules. Chemical reactions usually involve the making or breaking of
chemical bonds.
Oxidation, reduction,
dissociation, acid-base
neutralization and molecular
rearrangement are some of the commonly used kinds of chemical reactions.
A chemical reaction can be symbolically depicted through a
chemical equation. While in a non-nuclear chemical reaction the number and kind of atoms on both sides of the equation are equal
[32], for a nuclear reaction this holds true only for the nuclear particles viz. protons and neutrons.
The sequence of steps in which the reorganization of chemical bonds may be taking place in the course of a chemical reaction is called its
mechanism. A chemical reaction can be envisioned to take place in a number of steps, each of which may have a different speed. Many
reaction intermediates with variable stability can thus be envisaged during the course of a reaction. Reaction mechanisms are proposed to explain the
kinetics and the relative product mix of a reaction. Many
physical chemists specialize in exploring and proposing the mechanisms of various chemical reactions. Several empirical rules, like the
Woodward-Hoffmann rules often come handy while proposing a mechanism for a chemical reaction.
A stricter definition of chemical reactions has been proposed by
IUPAC[33] According to this definition, "a Chemical Reaction is a process that results in the interconversion of chemical species". Under this definition, a chemical reaction may be an
elementary reaction or a
stepwise reaction. An additional caveat is made, in that this definition includes cases where the
interconversion of conformers is experimentally observable. Such detectable chemical reactions normally involve sets of molecular entities as indicated by this definition, but it is often conceptually convenient to use the term also for changes involving single molecular entities (i.e. 'microscopic chemical events').
Energy
A
chemical reaction is invariably accompanied by an
increase or
decrease of
energy of the substances involved. Some energy is transferred between the surroundings and the reactants of the reaction in the form of
heat or
light, thus the products of a reaction may have more or less energy than the reactants. A reaction is said to be
exothermic if the final state is lower on the energy scale than the initial state; in case of
endothermic reactions the situation is otherwise.
Chemical reactions are invariably not possible unless the reactants surmount an energy barrier known as the
activation energy. The ''speed'' of a chemical reaction (at given temperature T) is related to the activation energy E, by the Boltzmann's population factor
- that is the probability of molecule to have energy greater than or equal to E at the given temperature T. This exponential dependence of a reaction rate on temperature is known as the
Arrhenius equation.
The activation energy necessary for a chemical reaction can be in the form of heat,
light,
electricity or mechanical
force in the form of
ultrasound[34].
A related concept
Free energy, which incorporates entropy considerations too, is a very useful means for predicting the feasibility of a reaction and determining the state of equilibrium of a chemical reaction, in
chemical thermodynamics. A reaction is feasible only if the total change in the
Gibbs free energy is negative,
; if it is equal to zero the chemical reaction is said to be at
equilibrium.
There are only a limited possible states of energy for electrons, atoms and molecules. These are determined by the rules of
quantum mechanics, which require
quantization of energy of a bound system. The atoms/molecules in an higher energy state are said to be excited. The molecules/atoms of substance in an excited energy state are often much more reactive, that is amenable to chemical reactions.
The phase of a substance is invariably determined by its energy and those of its surroundings. When the intermolecular forces of a substance are such that energy of the surroundings is not sufficient to overcome them, it occurs in a more ordered phase like liquid or solid
[35] as is the case with
water, it is
liquid at room temperature because its molecules are bound by
hydrogen bonds. Whereas
hydrogen sulfide (H
2S) is a gas at room temperature and standard pressure, as its molecules are bound by weaker
dipole-dipole interactions.
The transfer of energy from one chemical substance to other depend on the ''size'' of energy
quanta emitted from one substance. However, heat energy is easily transferred from almost any substance to another mainly because the vibrational and rotational energy levels in a substance are very closely placed. Because, the electronic energy levels are not so closely spaced, ultraviolet electromagnetic radiation is not transferred with equal felicity, as is also the case with electrical energy.
The existence of characteristic energy levels for different
chemical substances is useful for their identification by the analysis of
spectral lines of different kinds of spectra often used in chemical spectroscopy e.g.
IR,
microwave,
NMR,
ESR etc. This is used to identify the composition of remote objects - like stars and far galaxies - by analyzing their radiation (see
spectroscopy).
Emission spectrum of
iron
The term
chemical energy is often used to indicate the potential of a chemical substance to undergo a transformation through a
chemical reaction or transform other chemical substances.
Chemical laws
Main articles: Chemical law
Chemical reactions are governed by certain laws, which have become fundamental concepts in chemistry. Some of them are:
★
Law of conservation of mass, according to the modern physics it is actually
energy that is conserved, and that energy and mass are
related; a concept which becomes important in
nuclear chemistry.
★
Law of conservation of Energy leads to the important concepts of
equilibrium,
thermodynamics, and
kinetics.
★
Law of definite composition, although in many systems (notably biomacromolecules and minerals) the ratios tend to require large numbers, and are frequently represented as a fraction.
★
Law of multiple proportions
★
Hess's Law
★
Beer-Lambert law
★
Fick's law of diffusion
★
Rauolt's Law
★
Henry's law
★
Boyle's law (1662, relating pressure and volume)
★
Charles's law (1787, relating volume and temperature)
★
Gay-Lussac's law (1809, relating pressure and temperature)
★
Avogadro's law
Subdisciplines
Chemistry is typically divided into several major sub-disciplines. There are also several main cross-disciplinary and more specialized fields of chemistry.
[36]
★
Analytical chemistry is the analysis of material samples to gain an understanding of their
chemical composition and
structure. Analytical chemistry incorporates standardized experimental methods in chemistry. These methods may be used in all subdisciplines of chemistry, excluding purely theoretical chemistry.
★
Biochemistry is the study of the
chemicals,
chemical reactions and chemical
interactions that take place in living
organisms. Biochemistry and organic chemistry are closely related, as in
medicinal chemistry or
neurochemistry. Biochemistry is also associated with
molecular biology and
genetics.
★
Inorganic chemistry is the study of the properties and reactions of inorganic compounds. The distinction between organic and inorganic disciplines is not absolute and there is much overlap, most importantly in the sub-discipline of
organometallic chemistry.
★
Materials chemistry is the preparation, characterization, and understanding of substances with a useful function. The field is a new breadth of study in graduate programs, and it integrates elements from all classical areas of chemistry with a focus on fundamental issues that are unique to materials. Primary systems of study include the chemistry of condensed phases (solids, liquids,
polymers) and
interfaces between different phases.
★
Nuclear chemistry is the study of how subatomic particles come together and make nuclei. Modern
Transmutation is a large component of nuclear chemistry, and the
table of nuclides is an important result and tool for this field.
★
Organic chemistry is the study of the structure, properties, composition, mechanisms, and
reactions of
organic compounds. An organic compound is defined as any compound based on a carbon skeleton.
★
Physical chemistry is the study of the physical and fundamental basis of chemical systems and processes. In particular, the energetics and dynamics of such systems and processes are of interest to physical chemists. Important areas of study include
chemical thermodynamics,
chemical kinetics,
electrochemistry,
statistical mechanics, and
spectroscopy. Physical chemistry has large overlap with
molecular physics. Physical chemistry involves the use of
calculus in deriving equations. It is usually associated with
quantum chemistry and theoretical chemistry. Physical chemistry is a distinct discipline from
chemical physics.
★
Theoretical chemistry is the study of chemistry via fundamental theoretical reasoning (usually within
mathematics or
physics). In particular the application of
quantum mechanics to chemistry is called
quantum chemistry. Since the end of the
Second World War, the development of computers has allowed a systematic development of
computational chemistry, which is the art of developing and applying
computer programs for solving chemical problems. Theoretical chemistry has large overlap with (theoretical and experimental)
condensed matter physics and
molecular physics.
Other fields include
Astrochemistry,
Atmospheric chemistry,
Chemical Engineering,
Chemical biology,
Chemo-informatics,
Electrochemistry,
Environmental chemistry,
Flow chemistry,
Geochemistry,
Green chemistry,
History of chemistry,
Materials science,
Medicinal chemistry,
Molecular Biology,
Molecular genetics,
Nanotechnology,
Organometallic chemistry,
Petrochemistry,
Pharmacology,
Photochemistry,
Phytochemistry,
Polymer chemistry,
Solid-state chemistry,
Sonochemistry,
Supramolecular chemistry,
Surface chemistry,
Immunochemistry and
Thermochemistry.
Chemical industry
Main articles: chemical industry
The
chemical industry represents an important economic activity. The global top 50 chemical producers in 2004 had sales of 587 billion
US dollars with a profit margin of 8.1% and
research and development spending of 2.1% of total chemical sales.
[37]
References
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2. Chemistry. (n.d.). Merriam-Webster's Medical Dictionary. Retrieved August 19, 2007, from Dictionary.com website: http://dictionary.reference.com/browse/Chemistry
3. Affinity, That Elusive Dream - A Genealogy of the Chemical Revolution, , Kim, Mi Gyung, MIT Press, 2003, ISBN 0-262-11273-6
4. Dr. A. Zahoor (1997). JABIR IBN HAIYAN (Geber). University of Indonesia.
5. Paul Vallely. How Islamic inventors changed the world. ''The Independent''.
6. What is Chemistry?
7. Matter: Atoms from Democritus to Dalton by Anthony Carpi, Ph.D.
8. Theodore L. Brown, H. Eugene Lemay, Bruce Edward Bursten, H. Lemay. ''Chemistry: The Central Science''. Prentice Hall; 8 edition (1999). ISBN 0130103101. Pages 3-4.
9. It is sometimes called the central science because it is seen as occupying an intermediate position in a hierarchy of the sciences by "reductive level", between physics and biology. See Carsten Reinhardt. ''Chemical Sciences in the 20th Century: Bridging Boundaries''. Wiley-VCH, 2001. ISBN 3527302719. Pages 1-2.
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11. IUPAC Gold Book Definition
12. California Occupational Guide Number 22: Chemists[2]
13. http://www.chemheritage.org/explore/ancients-time.html
14. Will Durant (1980), ''The Age of Faith (The Story of Civilization, Volume 4)'', p. 162-186, Simon & Schuster, ISBN 0671012002:
15. Dr. K. Ajram (1992), ''Miracle of Islamic Science'', Appendix B, Knowledge House Publishers, ISBN 0911119434.
16. Will Durant (1935): Our Oriental Heritage: Simon & Schuster:
17. BBC - History - Robert Boyle (1627 - 1691) [3]
18. About: Chemistry - Time line of Element Discovery [4].
19. Alchemy Lab: History of Alchemy [5]
20. Strathern, P. (2000). ''Mendeleyev’s Dream – the Quest for the Elements.'' New York: Berkley Books.
21. The Sceptical Chymist, , Robert, Boyle, Dover Publications, Inc. (reprint), 1661, ISBN 0486428257
22. Traite de la chymie, , Christopher, Glaser, , 1663, as found in: Affinity, That Elusive Dream - A Genealogy of the Chemical Revolution, , Mi Gyung, Kim, The MIT Press, 2003, ISBN 0-262-11273-6
23. Philosophical Principles of Universal Chemistry, , George, E., Stahl, , 1730,
24. Dumas, J. B. (1837). 'Affinite' (lecture notes), vii, pg 4. “Statique chimique”, Paris: Academie des Sciences
25. General Chemistry, , Linus, Pauling, Dover Publications, Inc., 1947, ISBN 0486656225
26. Chemistry, 6th Ed., Chang, Raymond, , , McGraw Hill, 1998, ISBN 0-07-115221-0
27. General Chemistry Online - Companion Notes: Matter [6]
28. IUPAC Nomenclature of Organic Chemistry [7]
29. IUPAC Provisional Recommendations for the Nomenclature of Inorganic Chemistry (2004) [8]
30. Official SI Unit definitions
31. visionlearning: Chemical Bonding by Anthony Carpi, Ph. [9]
32. http://goldbook.iupac.org/C01034.html
33. Gold Book Link
34. http://www.newscientisttech.com/article/dn11427
35. http://www.chem4kids.com/files/matter_changes.html
36. The Canadian Encyclopedia: Chemistry Subdisciplines [10]
37. Top 50 Chemical Producers, , , , Chemical & Engineering News,
Further reading
Popular reading
★ Atkins, P.W. ''Galileo's Finger'' (Oxford University Press) ISBN 0198609418
★ Atkins, P.W. ''Atkins' Molecules'' (Cambridge University Press) ISBN 0521823978
★ Stwertka, A. ''A Guide to the Elements'' (Oxford University Press) ISBN 0195150279
Introductory undergraduate text books
★ Chang, Raymond. ''Chemistry'' 6th ed. Boston: James M. Smith, 1998. ISBN 0-07-115221-0.
★ Atkins, P.W., Overton, T., Rourke, J., Weller, M. and Armstrong, F. ''Shriver and Atkins inorganic chemistry'' (4th edition) 2006 (Oxford University Press) ISBN 0-19-926463-5
★ Clayden, J., Greeves, N., Warren, S., Wothers, P. ''Organic Chemistry'' 2000 (Oxford University Press) ISBN 0-19-850346-6
★ Voet and Voet ''Biochemistry'' (Wiley) ISBN 0-471-58651-X
Advanced Undergraduate-level or Graduate text books
★ Atkins, P.W. ''Physical Chemistry'' (Oxford University Press) ISBN 0-19-879285-9
★ Atkins, P.W. et al. ''Molecular Quantum Mechanics'' (Oxford University Press)
★ McWeeny, R. ''Coulson's Valence'' (Oxford Science Publications) ISBN 0-19-855144-4
★ Pauling, L. ''The Nature of the chemical bond'' (Cornell University Press) ISBN 0-8014-0333-2
★ Pauling, L., and Wilson, E. B. ''Introduction to Quantum Mechanics with Applications to Chemistry'' (Dover Publications) ISBN 0-486-64871-0
★ Stephenson, G. ''Mathematical Methods for Science Students'' (Longman)ISBN 0-582-44416-0
★ Smart and Moore ''Solid State Chemistry: An Introduction'' (Chapman and Hall) ISBN 0-412-40040-5
Professional societies
★
American Chemical Society
★
Chemical Institute of Canada
★
Chemical Society of Peru
★
International Union of Pure and Applied Chemistry
★
Royal Australian Chemical Institute
★
Royal Society of Chemistry
★
Society of Chemical Industry
★
World Association of Theoretical and Computational Chemists
See also
Lists
★
Common chemicals - Where to find common chemical components
★
List of basic chemistry topics
★
List of chemistry topics
★
List of chemists
★
List of compounds
★
List of important publications in chemistry
★
Periodic Table of the Elements
★
Timeline of chemistry
★
Unsolved problems in chemistry
External links
★
International Union of Pure and Applied Chemistry
★
IUPAC Nomenclature Home Page, see especially the "Gold Book" containing definitions of standard chemical terms
★
Interactive Mind Map of Chemistry
★
/ Chemical energetics
For a full list of external links and suppliers see .
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