Cesium - Chemistry Encyclopedia

Cesium is an alkali metal that reacts explosively with water and melts just above room temperature. The word "cesium" is derived from caesium (Latin for "sky blue").

Chalcogens - Chemistry Encyclopedia

The chalcogens are the name for the Periodic Table group 16 (or V1). The group consists of the elements: oxygen, sulfur, selenium, tellurium, and polonium.

Chemical Engineering - Chemistry Encyclopedia

Chemical engineers combine the science of chemistry with the discipline of engineering in order to manufacture materials and products essential to modern society. They are involved with the full scale of processes from the laboratory bench to the pilot plant and eventually at the manufacturing facility.

Chemical Informatics - Chemistry Encyclopedia

As with many new disciplines, the field of chemical informatics has neither a precise name nor a clear definition. It is variously called cheminformatics, chemoinformatics, and molecular informatics, among other terms.

Chemical Reactions - Chemistry Encyclopedia

A chemical reaction is a process in which one set of chemical substances (reactants) is converted into another (products). It involves making and breaking chemical bonds and the rearrangement of atoms.

Chemiluminescence - Chemistry Encyclopedia

When two molecules react chemically so that there is a release of energy (an exothermic reaction), that energy sometimes manifests itself not as heat but as light. This occurs because the energy excites the product molecules into which it has been funneled.

Chemistry and Energy - Chemistry Encyclopedia

Energy is central to our understanding of chemistry, for atoms adopt arrangements that correspond to the lowest possible energy and electrons in atoms adopt the lowest possible energy distribution. The adoption of lowest energy arrangements of atoms is responsible for the characteristic shapes of molecules.

Chemotherapy - Chemistry Encyclopedia

Chemotherapy is the controlled use of chemicals for a medicinal purpose. The term was coined by the German bacteriologist Paul Ehrlich, around 1900, when he examined aniline dyes and arsenicals as possible treatments for diseases such as trypanosomiasis and syphilis.

Chirality - Chemistry Encyclopedia

The term "chiral" (from the Greek for "hand") is applied to molecular systems whose asymmetry results in handedness; that is, the existence of a pair of nonsuperimposable mirror-image shapes (as illustrated by the relationship between one's right and left hands). Lord Kelvin coined the term "chirality" in 1884, (Eliel, p.

Chlorine - Chemistry Encyclopedia

Chlorine is one of the halogen family of elements and the first of that family to be discovered. Swedish chemist Carl Wilhelm Scheele produced chlorine in 1774 by the reaction of manganese dioxide (MnO2) with a solution of hydrochloric acid (HCl).

Cholecalciferol - Chemistry Encyclopedia

Cholecalciferol is known as vitamin D3. As early as 1870 people knew there was something in cod-liver oil that prevented rickets, a disease resulting in soft, deformed bones as a result of calcium deficiency.

Cholesterol - Chemistry Encyclopedia

Cholesterol is the most abundant sterol in animal tissues, making up as much as 25 percent of cell membranes. Cholesterol may be found free or as part of cholesteryl esters.

Chromium - Chemistry Encyclopedia

Chromium was first identified in 1797 by the French chemist Louis-Nicolas Vauquelin, who isolated it from crocoite, a mineral also called Siberian red lead. The name for chromium is taken from the Greek chroma, which means "color." This is a fitting name, because chromium compounds are often found in vividly colorful shades of green, red, or yellow.

Chromosome - Chemistry Encyclopedia

A chromosome is a compactly folded complex of DNA and proteins containing many genes, found in the nuclei of eukaryotic organisms and in the nucleoids of prokaryotic organisms.

Clones - Chemistry Encyclopedia

A clone is an organism or cell derived asexually (through mitosis) from a single ancestor cell. The genetic content of the newer cell (or of any individual cell of the organism) is identical to that of the ancestor cell.

Coal - Chemistry Encyclopedia

Coal, a naturally occurring combustible solid, is one of the world's most important and abundant energy sources. From its introduction 4,000 years ago as a fuel for heating and cooking, to its nineteenth- and twentieth-century use in generating electricity and as a chemical feedstock, coal, along with oil and natural gas, has remained an important source of energy.

Cobalt - Chemistry Encyclopedia

The name "cobalt" derives from the German word Kobold, meaning "mischievous spirit." Cobalt was first applied by sixteenth-century copper miners in the Hartz mountains of central Europe to gray metallic ores; this not only failed to produce copper when roasted, but also emitted dangerous fumes. It was found that the ores, after elimination of sulphur and arsenic by roasting, could be fused with sand to produce a blue glass called smalt.

Codon - Chemistry Encyclopedia

The genetic code (which includes the codon) serves as a basis for establishing how genes encoded in DNA are decoded into proteins. A critical interaction in protein synthesis is the interaction between the codon in messenger RNA (mRNA) and the anticodon in an aminoacyl-transfer RNA (aminoacyl-tRNA).

Coenzyme - Chemistry Encyclopedia

Coenzymes are small organic molecules that link to enzymes and whose presence is essential to the activity of those enzymes. Coenzymes belong to the larger group called cofactors, which also includes metal ions; cofactor is the more general term for small molecules required for the activity of their associated enzymes.

Cofactor - Chemistry Encyclopedia

Enzymes are either proteins (polymers of amino acids) or ribozymes (polymers of ribonucleotides). Some protein-based enzymes require small molecules called cofactors to become fully functional.

Collagen - Chemistry Encyclopedia

Collagen is a family of proteins; in animals these proteins play critical roles in tissue architecture, tissue strength, and cell to cell relationships. The major component of all connective tissue matrixes, collagen is found in tissues such as skin, blood vessels, bone, tendon, and ligament, and is characterized by tremendous strength.

Colligative Properties - Chemistry Encyclopedia

Colligative properties are those properties of solutions that depend on the number of dissolved particles in solution, but not on the identities of the solutes. For example, the freezing point of salt water is lower than that of pure water, due to the presence of the salt dissolved in the water.

James Chadwick - Chemistry Encyclopedia

Sir James Chadwick was born of humble origins on October 20, 1891, to John Joseph and Anne Mary Chadwick in Clarke Lane just outside of Bollington, England. Primarily raised by his grandparents, he won a scholarship to nearby Victoria University in Manchester, where he entered the physics program by mistake.

Emmett Chappelle - Chemistry Encyclopedia

There are many ways that we could determine if there is life on other planets.

Hilaire Chardonnet - Chemistry Encyclopedia

Louis-Marie-Hilaire Bernigaud, comte de Chardonnet, born in Besancon, France, is credited with having developed artificial silk, which came to be known as rayon. In the 1860s Chardonnet, originally trained as an engineer, assisted Louis Pasteur in an effort to save the French silk industry from an epidemic affecting silkworms.

Jacques Charles - Chemistry Encyclopedia

Jacques-Alexandre-César Charles was a mathematician and physicist remembered for his pioneering work with gases and hydrogen balloon flights. Charles was born on November 12, 1746, in Beaugency, Loiret, France; his first occupation was as a clerk at the Ministry of Finance in Paris.

Michel Chevreul - Chemistry Encyclopedia

Michel-Eugène Chevreul was a chemist whose career spanned the greater part of the nineteenth century. He was born in Angers, France, on August 31, 1786, and died in Paris on April 9, 1889.

Per Theodor Cleve - Chemistry Encyclopedia

Per Theodor Cleve was a nineteenth-century expert in agricultural chemistry, inorganic and organic chemistries, geology, mineralogy, and oceanography.