Chemistry is a physical science concerned with the composition, structure, and properties of matter. It also deals with the changes that matter undergoes during chemical reactions. It incorporates the studies of various atoms, molecules, crystals and other aggregates which can be combined or isolated and concepts of energy and entropy through which chemical processes occur. Modern chemistry (from the Egyptian kÄ“me, meaning “earth”) evolved from alchemy following the chemical revolution (1773).
There are many subfields of chemistry. Most of these are grouped by the type of matter being observed or studied. These subfields include inorganic chemistry, organic chemistry, biochemistry, physical chemistry, analytical chemistry, neurochemistry, and many others. These subfields are readily recognized as disciplines or sub-disciplines. Chemistry is often referred to as “the central science” as it connects the other natural sciences together. Traditional chemistry involves the study of interactions between substances in a chemistry laboratory.
A chemical reaction is a transformation of a substance into another substance. This process is usually depicted using a chemical equation. The nature of chemical reactions a substance undergoes and the energy changes it may take on are confined to basic rules, known as chemical laws. Energy and entropy factors are important in almost all chemical studies. The substance is classified by structure, phase, and chemical makeup, and it is analyzed using tools of chemical analysis. These tools include spectroscopes and chromatographs, among others.
Chemistry plays an important part in scientific education. In high school and college, most students are required to study “general chemistry” in order to be introduced to a wide array of concepts that enable a student to gain the skills and tools useful in advanced chemistry. Scientists that are involved in chemical research are called chemists. Most chemists specialize in one or more sub-disciplines of chemistry.
The history of chemistry is quite extensive. Ancient Egyptians founded the art of synthetic “wet” chemistry as far back as 4000 years ago. By 1000 BC ancient cultures were utilizing technologies that formed the basis for chemistry as we know it today. Some ancient forms of chemistry include: extracting metal from ores, making pottery and glazes, fermenting beer and wine, making pigments for painting, extraction of chemicals from plants for medicines. These early people also used metals and chemicals to make cheese, dye cloth, tan leather, make soap, make glass, and make alloys such as bronze.
Metallurgy (the art and science of processing ores to get metals) was used in ancient India. The early crude form was a process of burning ore. Many scholars of that time thought there was an easier way to form gold by manipulating cheaper metals. This gave way to alchemy and the search for a stone (Philosopher’s Stone) that was believed to bring about the transformation of gold by mere touch.
Atomism dates back to 440 BC. Some medieval Arabs and Persians were thought to be the earliest chemists. They introduced controlled experiments, and discovered numerous substances. The most influential Muslim chemists were Geber (d. 815), al-Kindi (d. 873), al-Razi (d. 925), and al-Biruni (d. 1048). Alchemy and chemistry became more known in Europe during the recurring incidence of the plague in the Dark Ages. This time gave rise to the need for medicines. It was believed that there was a medicine known as the Elixir of Life that could cure all ailments and diseases, but like the Philosopher’s Stone, it was never found.
Alchemy was one science that took a long time to perfect. Many practitioners considered it an intellectual pursuit. Paracelsus (1493 – 1541) rejected early alchemy and with little understanding of the science, formed a hybrid of alchemy and science what was eventually called iatrochemistry. Other philosophers demanded more strictness in mathematics and scientific applications, which led to a scientific revolution. Robert Boyle (1627 – 1691) came up with an equation (known as Boyle’s Law) pertaining to the characteristics of gaseous state. Antoine Lavoisier (1743 – 1794) developed the theory of conservation of mass in 1783. John Dalton developed the Atomic Theory in 1800.
The Law of Conservation of Mass resulted in new formulas of chemistry which was based largely on Lavoisier’s work. His contributions to chemistry were a result of a conscious effort to fit all experiments into a single theory. He established consistent chemical balance, used oxygen to overthrow the phlogiston theory, developed new systems of chemical classifications, and contributed to the modern metric system. Lavoisier also translated archaic technical language of chemistry into more easily understood language that could be read by the mostly uneducated population. His translations peaked public interest and chemistry gained more interest. His work led to what is known as the chemical revolution and he is often celebrated as the “Father of Modern Chemistry”.
Chemical reactions are ruled by certain laws, which have become mainstream concepts in modern chemistry. Of these, the more widely known and used laws named for their developers, are: Avogadro’s Law, Beer-Lambert Law, Boyle’s Law (relating to pressure and volume), Charles’s Law (volume and temperature), Fick’s Law, Gay-Lussac’s Law (pressure and temperature), Henry’s Law, and Hess’s Law. Other widely used laws are the Laws of Conservation of Energy, Laws of Conservation of Mass, Law of Definite Composition, and Law of Multiple Proportions.
Among the main subfields of chemistry there are also many more specialized fields. The huge list includes:
agrochemistry, astrochemistry, atmospheric chemistry, chemical engineering, chemical biology, chemo-informatics, electrochemistry, environmental chemistry, flavor chemistry, flow chemistry, geochemistry, green chemistry, histochemistry (history of chemistry), hydrogenation chemistry, mathematical chemistry, mechanochemistry, medicinal chemistry, molecular biology, nanotechnology, natural product chemistry, oenology, neurochemistry, organometallic chemistry, petrochemistry, pharmacology, photochemistry, physical organic chemistry, phytochemistry, polymer chemistry, radiochemistry, solid-state chemistry, sonochemistry, supramolecular chemistry, surface chemistry, synthetic chemistry, thermochemistry, and many others.