Chemistry and Goals of Chemists

Chemistry is a science of substances, their properties,most complex plants and animals.
and how and why materials combine or separate toInorganic chemistry: Inorganic chemistry is the study of
form different substances. Atoms, molecules andthe chemistry of all the elements in the periodic table
compounds are the involved ones in the study ofexcept for carbon. Like their cousins in the field of
Chemistry. In other words, it is how atoms interact toorganic chemistry, inorganic chemists have provided
form molecules and how molecules interact with eachthe world with countless numbers of useful products,
other. It also looks into the composition of substancesincluding fertilizers, alloys, ceramics, household cleaning
and their properties. The outer electron orbits or shellsproducts, building materials, water softening and
primarily determine the chemical characteristics of apurification systems, paints and stains, computer chips
material and whether materials will chemically combine.and other electronic components, and beauty products.
Thus Chemistry is the study of the composition ofThe more than 100 elements included in the field of
matter and the changes that take place in thatinorganic chemistry have a staggering variety of
composition. If we place a bar of iron outside ourproperties. Some are gases, others are solid, and a
window, the iron bar will soon begin to rust. If we pourfew are liquid. Some are so reactive that they have to
vinegar on baking soda, the mixture fizzes. If we hold abe stored in special containers, while others are so
sugar cube over a flame, the sugar begins to turninert (inactive) that they virtually never react with other
brown and give off steam. The goal of chemistry is toelements. Some are so common they can be
understand the composition of substances such asproduced for only a few cents a pound, while others
iron, vinegar, baking soda, and sugar and to understandare so rare that they cost hundreds of dollars an
what happens during the changes described here.ounce. Because of this wide variety of elements and
The term chemistry has grown out of an earlier fieldproperties, most inorganic chemists concentrate on a
of study known as alchemy. Alchemy has beensingle element or family of elements or on certain
described as a kind of pre-chemistry, in which scholarstypes of reactions.
studied the nature of matter but without the formalPhysical chemistry: Physical chemistry is the branch of
scientific approach that modern chemists use. Thechemistry that investigates the physical properties of
term alchemy is probably based on the Arabic namematerials and relates these properties to the structure
for Egypt, al-Kimia, or the "black country." Ancientof the substance. Physical chemists study both organic
scholars learned a great deal about matter, usually byand inorganic compounds and measure such variables
trial- and-error methods. For example, the Egyptiansas the temperature needed to liquefy a solid, the
mastered many technical procedures such as makingenergy of the light absorbed by a substance, and the
different types of metals, manufacturing colored glass,heat required to accomplish a chemical transformation.
dying cloth, and extracting oils from plants. AlchemistsA computer is used to calculate the properties of a
of the Middle Ages discovered a number of elementsmaterial and compare these assumptions to laboratory
and compounds and perfected other chemicalmeasurements. Physical chemistry is responsible for
techniques, such as distillation and crystallization. Thethe theories and understanding of the physical
modern subject of chemistry did not appear, however,phenomena utilized in organic and inorganic chemistry.
until the eighteenth century. At that point, scholarsAnalytical chemistry: Analytical chemistry is that field of
began to recognize that research on the nature ofchemistry concerned with the identification of materials
matter had to be conducted according to certainand with the determination of the percentage
specific rules. Among these rules was one stating thatcomposition of compounds and mixtures. These two
ideas in chemistry had to be subjected to experimentallines of research are known, respectively, as qualitative
tests. Nowadays keeping in view the overallanalysis and quantitative analysis. Two of the oldest
significance and versatility of chemistry, we can saytechniques used in analytical chemistry are gravimetric
that:and volumetric analysis. Gravimetric analysis refers to
Chemistry is a science:  There is only one sanctionedthe process by which a substance is precipitated
procedure for determining whether a statement about(changed to a solid) out of solution and then dried and
matter is really chemistry: the exhaustive, inefficient, butweighed. Volumetric analysis involves the reaction
highly successful scientific method. Chemists oftenbetween two liquids in order to determine the
arrive at new results by nonscientific means (like luckcomposition of one or both of the liquids.
or sheer creativity), but their work isn't chemistry unlessIn the last half of the twentieth century, a number of
it can be reproduced and verified scientifically.mechanical systems have been developed for use in
Chemistry is a systematic study: Chemists haveanalytical research. For example, spectroscopy is the
devised several good methods for solving problemsprocess by which an unknown sample is excited (or
and making observations. For example, analyticalenergized) by heating or by some other process. The
chemists often use protocols (thoroughly testedradiation given off by the hot sample can then be
recipes) for determining the concentrations ofanalyzed to determine what elements are present.
substances in a sample. Chemists use well-definedVarious forms of spectroscopy are available (X-ray,
techniques like spectroscopy and chromatography toinfrared, and ultraviolet, for example) depending on the
study new or unknown substances.form of radiation analyzed. Other analytical techniques
Chemistry is the study of the composition andnow in use include optical and electron microscopy,
properties of matter:  Chemistry is the study of thenuclear magnetic resonance (MRI; used to produce a
composition and properties of matter as it answersthree-dimensional image), mass spectrometry (used to
questions like, "What kind of stuff is a sample madeidentify and find out the mass of particles contained in
of? What does the sample look like on a moleculara mixture), and various forms of chromatography
scale? How does the structure of the material(used to identify the components of mixtures).
determine its properties? How do the properties of theOther fields of chemistry: The division of chemistry into
material change when we increase temperature, orfour major fields is in some ways misleading and
pressure, or some other environmental variable?"inaccurate. In the first place, each of these four fields is
Chemistry is the study of the reactivity of substances:so large that no chemist is an authority in any one field.
 Chemistry is the study of the reactivity ofAn inorganic chemist might specialize in the chemistry
substances as one material can be changed intoof sulfur, the chemistry of nitrogen, the chemistry of
another by a chemical reaction. A complex substancethe inert gases, or in even more specialized topics.
can by made from simpler ones. Chemical compoundsSecondly, many fields have developed within one of
can break down into simpler substances. For example,the four major areas, and many other fields cross two
fuels burn, food cooks, leaves turn their colors in theor more of the major areas. For an example of
fall, cells grow, medicines cure and it is both theirspecialization, the subject of biochemistry is considered
chemistry and the chemistry which is concerned witha subspecialty of organic chemistry. It is concerned
the essential processes that make these changeswith organic compounds that occur within living
happen. Today, the science of chemistry is oftensystems. An example of a cross-discipline subject is
divided into four major areas: organic, inorganic,bioinorganic chemistry. Bioinorganic chemistry is the
physical, and analytical chemistry. Each disciplinescience dealing with the role of inorganic elements and
investigates a different aspect of the properties andtheir compounds (such as iron, copper, and sulfur) in
reactions of matter.living organisms. At present, chemists explore the
Organic chemistry: Organic chemistry is the study ofboundaries of chemistry and its connections with other
carbon compounds. That definition sometimes puzzlessciences, such as biology, environmental science,
beginning chemistry students because more than 100geology, mathematics, and physics. A chemist today
chemical elements are known. How does it happenmay even have a so-called nontraditional occupation.
that one large field of chemistry is devoted to theHe or she may be a pharmaceutical salesperson, a
study of only one of those elements and itstechnical writer, a science librarian, an investment
compounds? The answer to that question is thatbroker, or a patent lawyer, since discoveries by a
carbon is a most unusual element. It is the only elementtraditional chemist may expand and diversify into a
whose atoms are able to combine with each other invariety of fields that encompass our whole society.
apparently endless combinations. Many organicChemists have two major goals. One is to find out the
compounds consist of dozens, hundreds, or evencomposition of matter in order to learn what elements
thousands of carbon atoms joined to each other in aare present in a given sample and in what percentage
continuous chain. Other organic compounds consist ofand arrangement. This type of research is known as
carbon chains with other carbon chains branching offanalysis. A second goal is to invent new substances
them. Still other organic compounds consist of carbonthat replicate or are different from those found in
atoms arranged in rings, cages, spheres, or othernature. This form of research is known as synthesis. In
geometric forms. The scope of organic chemistry canmany cases, analysis leads to synthesis. That is,
be appreciated by knowing that more than 90 percentchemists may find that some naturally occurring
of all compounds known to science (more than 10substance is a good painkiller. That discovery may
million compounds) are organic compounds. Organicsuggest new avenues of research that will lead to a
chemistry is of special interest because it deals withsynthetic (human-made) product similar to the natural
many of the compounds that we encounter in ourproduct, but with other desirable properties (and usually
everyday lives: natural and synthetic rubber, vitamins,lower cost). Many of the substances that chemistry
carbohydrates, proteins, fats and oils, cloth, plastics,has produced for human use have been developed by
paper, and most of the compounds that make up allthis process of analysis and synthesis.
living organisms, from simple one-cell bacteria to the