Cosma / Communication / Knowledge / Realm / Physical / Matter / Molecule

Deep in the sea
all molecules repeat
the patterns of one another
till complex new ones are formed.
They make others like themselves
and a new dance starts.

Growing in size and complexity
living things
masses of atoms
DNA, protein
dancing a pattern ever more intricate. — Richard Feynman




molecule : the smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms — Webster   See also OneLook


Roget’s II (, Merriam-Webster Thesaurus, Visuwords


Molecule is an electrically neutral group of two or more atoms held together by chemical bonds. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, as with oxygen (O2); or it may be heteronuclear, a chemical compound composed of more than one element, as with water (H2O). Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are generally not considered single molecules.

Molecules as components of matter are common in organic substances (and therefore biochemistry). However, the majority of familiar solid substances on Earth, including most of the minerals that make up the crust, mantle, and core of the Earth, contain many chemical bonds, but are not made of identifiable molecules. Also, no typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond, quartz, or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding, which means that solid metals are also not made of molecules. — Wikipedia

Molecule (Encyclopædia Britannica)

Merck Index: Chemicals, Drugs and Biologicals (Royal Society of Chemistry)
Merck Index (Wikipedia)


Step by Step Chemistry (Wolfram Alpha)




Molecular physics is the study of the physical properties of molecules, the chemical bonds between atoms as well as the molecular dynamics. Its most important experimental techniques are the various types of spectroscopy; scattering is also used. The field is closely related to atomic physics and overlaps greatly with theoretical chemistry, physical chemistry and chemical physics.

In addition to the electronic excitation states which are known from atoms, molecules exhibit rotational and vibrational modes whose energy levels are quantized. The smallest energy differences exist between different rotational states: pure rotational spectra are in the far infrared region (about 30 – 150 µm wavelength) of the electromagnetic spectrum. Vibrational spectra are in the near infrared (about 1 – 5 µm) and spectra resulting from electronic transitions are mostly in the visible and ultraviolet regions. From measuring rotational and vibrational spectra properties of molecules like the distance between the nuclei can be specifically calculated. — Wikipedia

Bond Breaker 101 (TestTubeGames)
Chemistry at the Space Time Limit (CaSTL)

Visualizing vibrational normal modes of a single molecule with atomically confined light (Joonhee Lee, Et al., Nature)

Inorganic chemistry Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. — Wikipedia

List of Inorganic Compounds (Wikipedia)
Inorganic Chemistry (Eric Weisstein’s World of Chemistry, Wolfram Research)

Organic chemistry is a branch of chemistry that studies the structure, properties and reactions of organic compounds, which contain carbon-carbon covalent bonds. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical (in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (included in many biochemicals) and the halogens. — Wikipedia

Organic Chemistry (Eric Weisstein’s World of Chemistry, Wolfram Research)


ChemDoodle Applications (iChemLabs)



Molecule Campaigns (Kickstarter)
Molecule Campaigns (Indiegogo)


Molecule Gifts (Zazzle)


Library of Congress # QD71 Analytical Chemistry (UPenn Online Books)

WorldCat, Library of Congress, UPenn Online Books, Open Library




The science of macaroni salad: What’s in a molecule? (Josh Kurz, TED-Ed)

What is the shape of a molecule? (George Zaidan and Charles Morton, TED-Ed)

What triggers a chemical reaction? (Kareem Jarrah, TED-Ed)

MathMol: An introductory site for Molecular Modeling

Common Molecules (Reciprocal Net project, Indiana University)

Molecules & Bonding (ChemMatters, American Chemical Society)
Organic Chemistry (ChemMatters, American Chemical Society)

Chem Helper: Organic Chemistry Help!

MERLOT: Multimedia Educational Resource for Learning and Online Teaching
OER Commons: Open Educational Resources


Crash Course Chemistry (YouTube Playlist)

Crash Course Organic Chemistry (YouTube Playlist)

General Chemistry I: Atoms, Molecules, and Bonding (MITx)
General Chemistry II: Chemical Equilibrium, Kinetics, and Transition (MITx)

Chemistry Department Courses (MIT OpenCourseWare)
Inorganic Chemistry (MIT OpenCourseWare)
Organic Chemistry (MIT OpenCourseWare)

Chemistry Courses (edX)

MicroBachelors Program in University Chemistry (HarvardX)



Molecular and Cellular Biologists (CareerOneStop, U.S. Department of Labor, Employment and Training Administration)
Analytical Chemistry (American Chemical Society)

Inorganic Chemistry Careers (American Chemical Society)
Organic Chemistry Careers (American Chemical Society)


American Chemical Society Division of Analytical Chemistry
Molecular Physics Group (Institute Of Physics)
Molecular Structure Center (Indiana University)

Division of Inorganic Chemistry (American Chemical Society)
Division of Organic Chemistry (American Chemical Society)


International Journal of Molecular Sciences
Journal of Molecular Sciences

Inorganic Chemistry (Nature)
Organic chemistry (Nature)

Molecule (
Molecule (NPR Archives)


Molecule (ISBNdb)



Molecule (





Bond Breaker 3 (TestTubeGames, CaSTL Research Center, UC Irvine)



Here are links to pages about closely related subjects.

Knowledge Realm


Law (Constant) Relativity
Force Gravity, Electromagnetism (Light, Color)
Matter (Microscope) Molecule, Atom (Periodic Table), Particle

Universe (Astronomical Instrument)
Galaxy Milky Way, Andromeda
Planetary System Star, Brown Dwarf, Planet, Moon

Our Neighborhood
Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Trans-Neptunian Object
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid


1.   The resources on this page are are organized by a classification scheme developed exclusively for Cosma.