Chemistry is the branch of science that deals with the qualities of both pure elements and chemical compounds and the natural laws that describe their actions.
Chemistry is a huge science, midway between physics and biology in terms of the order of things. Its various areas of specialized study include natural, synthetic, inorganic, organic, biochemistry, chemical engineering, molecular, quantum mechanical, and the very important science of nanochemistry. Topics dealt with include different types of chemical bonds (both in natural and exotic matter), phase changes in matter; equilibrium and non-equilibrium thermodynamics; combustion; chemical reaction rates and equilibrium; the chemical analysis and structure of substances, and the study, synthesis and analysis of acids, salts, enzymes, polymers, organic compounds, metals, pseudometals, superatoms, or any other natural or artificial substances, as well as analogous structures composed of exotic materials such as magmatter.
- Adamant - Text by Stephen Inniss
A mixture of carbon allotropes in which the carbon-carbon bonds are carefully arranged through nanotech mechanochemistry to confer greater hardness, toughness, and flexibility than that of standard diamondoid.
- Ammonia - Text by M. Alan Kazlev
A colourless, pungent, corrosive gas, NH3, extensively used in the manufacture of crude organobiota and a wide variety of nitrogen-containing organic and inorganic products and chemicals. In is an important component in the atmosphere of some Jovian planets.
- Buckyball - Text by M. Alan Kazlev
Short for buckminsterfullerene, and part of a larger class of molecules known as as fullerenes, the third form of carbon. Any of a number of roughly spherical molecule formed of a large number of carbon atoms. The smallest and most common form of buckminsterfullerene is C60; it has 60 carbon atoms in a soccer-ball shape, but there are many variants. The third form of carbon. After atomic age visionary thinker and inventer R. Buckminster Fuller's building designs.
- Catalyst - Text by M. Alan Kazlev
An agent that can produce change in its surrounding environment without undergoing any change in itself. May be an element (e.g. carbon in carbon burning of very hot stars), a chemical compound, an enzyme, a bionanite, or a meme.
- Chemical Engineering - Text by M. Alan Kazlev, based on the original by Robert J. Hall
The macro-, micro-, meso- or nano-scale chemical conversion of raw materials into such end products as bioplastoids, synthetic petroleum products, dumb (macroscale) detergents, plastics, natural and synthetic fuels, pharmaceuticals, fullerenes, hardcopy paper, and industrial chemicals. While most products can be easily synthesized with any household nanofab, chemical engineering is still important in the mass-production of large quantities of material in large chemical plants.
- Covalent Bond - Text by M. Alan Kazlev
In chemistry, when two atoms share one or more a pairs of electrons.
- Cryonics - Text by Anders Sandberg in his Transhuman Terminology
Science and tech that deals with low temperatures.
- Crystal - Text by Stephen Inniss; original by M. Alan Kazlev
In materials science and solid state physics, any solid material, whether natural or artificial, inorganic or organic, in which the molecules, ions, or atoms are arranged in an orderly repeating pattern that extends in all three spatial directions. An early benefit of nanoscale technologies was improved manipulation of crystal size and type in bulk materials; the various substances termed 'diamondoid' are but one example of this. Colloquially, a crystal is any object that exhibits a well defined geometric shape as a result of its internal order. Such objects are often aesthetically pleasing, and may have artistic and cultural value.
- Element - Text by M. Alan Kazlev
A chemically pure substance composed of atoms of a single type.
- Emergence - Text by M. Alan Kazlev
The process whereby more Complex systems arise from simpler systems. Emergence is unanticipated and cannot be directly deduced from the lower-level behaviors. Usually, The nature and behaviour of the more complex system cannot be defined in terms of its components. For example, the organization of a nanecology is said to emerge from the interactions of the lower-level behaviors of the nanites, and not from any single nanite. The concept has applications in many fields, from chemistry to biology to psychology and the social sciences.
- Emission Spectrum - Text by M. Alan Kazlev
Discontinuous spectrum, consisting of bright bands, that is emitted by atoms or molecules. Each chemical element and compound has its own distinct emission spectrum.
- Excited State - Text by M. Alan Kazlev
The state of an atom or molecule when not all electrons are in the lowest possible levels. Compare with ground state.
- Fullerene - Text by Stephen Inniss
Any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube, as opposed to forms of carbon such as graphite or diamond which make extended networks that lead to crystals, or to amorphous forms of carbon such as soot.
- Gas - Text by M. Alan Kazlev
Phase of matter that has low density, is easily compressible and expandable, and expands spontaneously when placed in a larger container. The atoms or molecules are widely separated and move around freely.
- Geochemistry - Text by M. Alan Kazlev
The study of materials and chemical reactions in rocks, minerals, magma, seawater, and soil.
- Ground State - Text by M. Alan Kazlev
The lowest energy state for an atom or molecule. When an atom is in its ground state, its electrons fill the lowest energy orbitals completely before they begin to occupy higher energy orbitals, and they fill subshells. Ground state may also refer to movThese can also refer to movement; a molecule's vibrational, rotational and translational states. Compare with excited state.
- Group (chemistry) - Text by M. Alan Kazlev
 A substructure that imparts characteristic chemical behaviors to a molecule, for example, a carboxylic acid group.
 A vertical column on the periodic table, for example, the halogens. Elements that belong to the same group usually show chemical similarities, although the element at the top of the group is usually atypical.
- Helium - Text by Stephen Inniss after the original by M. Alan Kazlev
The second lightest naturally occurring atomic element, and the most common in the universe after hydrogen.
- Hydrogen - Text by M. Alan Kazlev
The lightest and most common element in the universe. The normal hydrogen atom has only one proton and one electron. The much rarer and radioactive isotopes deuterium has a neutron as well, and the even rarer (and radioactive) and tritium has two neutrons. Hydrogen is found in great quantities in stars, the atmosphere of gas giants, and the interstellar gaseous medium. About three quarters of all conventional matter in the universe is hydrogen.
- Hydrogen Bond - Text by M. Alan Kazlev
A strong electrostatic attraction between two independent polar molecules;
in which the charges are unevenly distributed, usually containing electronegative atoms like nitrogen, oxygen, or fluorine. These atoms strongly attract electrons, and the hydrogen atom serves as a bridge between them. The hydrogen atom has a covalent link with one of the electronegative atoms, and forms an electrostatic link with another electronegative atom in the same or another molecule. The hydrogen bond plays an important role in molecular biology, biomesotech and bionanotech. Hydrogen bonding is what makes water stick to itself, and is responsible for the structure of ice. It is much weaker than the ionic or covalent bonds, though stronger than other kinds of intermolecular bonds.
- Ionic Bond - Text by M. Alan Kazlev
Chemical bond that results from the attraction of oppositely charged ions.
The atoms of metallic elements, such as sodium, lose their outer electrons easily to become positively charged but ions, while the atoms of nonmetals, such as chlorine, easily gain electrons and become to become negatively charged ions. The combination of these two stable ions results in a stable molecule or crystal. In an ionic crystal like sodium chloride (common salt), no discrete diatomic molecules exist, and the entire crystal functions as a single giant molecule.
- Isotope - Text by M. Alan Kazlev
An atom that posses a different number of neutrons to others of the same element, giving it a different atomic weight. Each element may have many possible isotopic forms, but only a few are naturally stable.
- Lithium - Text by M. Alan Kazlev
Soft, silver-white metallic element, the lightest of all metals, occurring combined in certain minerals. Symbol: Li; atomic weight 6.939. The amat version is very popular in industry and for ship drives - since anti-lithium is a metal it is easy to run a current through it to give it electromagnetic properties for manipulation. A strong magnetic field can also be used; while lithium isn't paramagnetic the weak diamagnetism can keep it suspended in a sufficiently strong field.
- Materials Science - Text by M. Alan Kazlev
The study and application of the nature and properties of various materials, including alloys, ceramics, composites, gels, membranes, polymers, synthetics, and biological materials, as well as completely neohylogenic nano materials, on the macro, micro, nano, and pico scale.
- Metallic Bond - Text by M. Alan Kazlev
Chemical bond responsible for the crystalline structure of pure metals. All the valence electrons are shared collectively by all the atoms in the crystal. The electrons behave like a free gas moving within the lattice of fixed, positive ionic cores. Because of this extreme mobility of electrons, metal has a very high thermal and electrical conductivity.
- Metallurgy - Text by M. Alan Kazlev based on original by Robert J. Hall
The study of metals, including their properties and processing and efforts to create completely new alloys.
- Methane - Text by M. Alan Kazlev
(CH4) an odorless, colorless, flammable gas that forms an important part of the atmosphere of many eogaian, eovenusian, and jovian worlds.
- Molecule - Text by Stephen Inniss
Two or more atoms of ordinary matter joined by a shared electron cloud and forming a chemical bond. In some usages, analogous arrangements of exotic matter.
- Non-biodegradable - Text by M. Alan Kazlev
Materials that are not broken down by natural microorganisms in the environment; they require special bionano or hylonano or artificial organisms that use the same to be disassembled or recycled.
- Organic Compounds - Text by M. Alan Kazlev
Organic chemical compounds include alcohols, aldehydes, ketones, carboxylic acids, carbohydrates, lipids, and proteins, necessary for carbon-based life, and also bionano. There are countless different organic compounds known, and many more created or synthesized. See also organic chemistry.
- Periodic Table - Text by M. Alan Kazlev; modified by Stephen Inniss
An arrangement of the chemical elements according to increasing atomic number in which each row (period) in the table corresponds to the filling of a quantum shell of electrons, and elements with similar properties fall into the same columns
- Plastic (physics/chemistry) - Text by M. Alan Kazlev
A material with the properties of a solid but capable of flowing under pressure. Some of the layers of the mantle of a large Terrestrial Class planet are plastic.
- Programmable Quantum-Dot Arrays - Text by John Edds
Array of variable quantum dots that are incorporated into the surfaces of electrically or photonically conductive nanostructured composite films and nanofibers, capable of creating surfaces and composites with a wide array of optical and electrical characteristics.
- Relative Cosmic Abundance of Elements - Text by Stephen Inniss
The universe consists almost entirely of hydrogen and helium, but of the impurities created by the processes in stars made intelligent life possible, and their relative natural abundance continues to shape the evolution of biology, technology, and society.
- Stable Transuranic Elements - Text by Ithuriel
Superheavy nuclei with proton numbers greater than 112 and half lives of at least one year.
- Synano - Text by Stephen Inniss
Nanotechnology that integrates hylonano ("dry", or inorganic nanotech) with bionano ("wet", or organic nanotech).
- Toxicology - Text by M. Alan Kazlev based on original by Robert J. Hall
The study of the adverse effect of poisonous or metabolically harmful chemicals on terragen and alien bionts. Toxicologists are experts in a variety of toxins, their symptoms, effects and various means to treat them. They use acquired and augmented knowledge, skills, databases, and expert systems from a variety of disciplines, including physiology, biochemistry, molecular biology, immunology, pharmacology, xenology, bionanotech, and nanophagistics.
- Tritium - Text by M. Alan Kazlev
Radioactive isotope of hydrogen with mass (nucleon) number of 3. It has a half-life of 12.5 years. The nucleus contains one proton and two neutrons. Tritium is widely used in fusion reactors and for fusion-based interplanetary ships.
Text by M. Alan Kazlev
modified from the original write-up by Robert J. Hall
Initially published on 24 September 2001.