electronegativity, negativity - (chemistry) the tendency of an atom or radical to attract electrons in the formation of an ionic bond

atomic mass - (chemistry) the mass (in atomic mass units) of an isotope of an element

atomic weight, relative atomic mass - (chemistry) the ratio of the atomic mass of an element to half the atomic mass of carbon-12

molecular weight, relative molecular mass - (chemistry) the sum of the relative atomic masses of the constituent atoms of a molecule

valence, valency - (chemistry) a property of atoms or radicals; their combining power given in terms of the number of hydrogen atoms (or the equivalent)

pH, pH scale - (chemistry) p(otential of) H(ydrogen); the logarithm of the reciprocal of hydrogen-ion concentration in gram atoms per liter; provides a measure on a scale from 0 to 14 of the acidity or alkalinity of a solution (where 7 is neutral and greater than 7 is acidic and less than 7 is basic)

Dalton's law of partial pressures, law of partial pressures, Dalton's law - (chemistry and physics) law stating that the pressure exerted by a mixture of gases equals the sum of the partial pressures of the gases in the mixture; the pressure of a gas in a mixture equals the pressure it would exert if it occupied the same volume alone at the same temperature

distribution law - (chemistry) the total energy in an assembly of molecules is not distributed equally but is distributed around an average value according to a statistical distribution

equilibrium law, law of chemical equilibrium - (chemistry) the principle that (at chemical equilibrium) in a reversible reaction the ratio of the rate of the forward reaction to the rate of the reverse reaction is a constant for that reaction

Henry's law - (chemistry) law formulated by the English chemist William Henry; the amount of a gas that will be absorbed by water increases as the gas pressure increases

law of constant proportion, law of definite proportions - (chemistry) law stating that every pure substance always contains the same elements combined in the same proportions by weight

law of equivalent proportions, law of reciprocal proportions - (chemistry) law stating that the proportions in which two elements separately combine with a third element are also the proportions in which they combine together

Dalton's law, law of multiple proportions - (chemistry) law stating that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation

law of mass action - (chemistry) the law that states the following principle: the rate of a chemical reaction is directly proportional to the molecular concentrations of the reacting substances

Mendeleev's law, periodic law - (chemistry) the principle that chemical properties of the elements are periodic functions of their atomic numbers

natural science - the sciences involved in the study of the physical world and its phenomena

chemoimmunology, immunochemistry - the field of chemistry concerned with chemical processes in immunology (such as chemical studies of antigens and antibodies)

organic chemistry - the chemistry of compounds containing carbon (originally defined as the chemistry of substances produced by living organisms but now extended to substances synthesized artificially)

organic chemistry - the chemistry of compounds containing carbon (originally defined as the chemistry of substances produced by living organisms but now extended to substances synthesized artificially)

inorganic chemistry - the chemistry of compounds that do not contain hydrocarbon radicals

physical chemistry - the branch of chemistry dealing with the physical properties of chemical substances

electrochemistry - branch of chemistry that deals with the chemical action of electricity and the production of electricity by chemical reactions

femtochemistry - the branch of chemistry that studies elementary (often very fast) chemical reactions as they occur; the experimental methods are often based on the use of femtosecond laser pulses

geochemistry - the chemistry of the earth's crust

photochemistry - branch of chemistry that deals with the chemical action of light

nuclear chemistry, radiochemistry - the chemistry of radioactive substances

atomist theory, atomistic theory, atomic theory, atomism - (chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles; "the ancient Greek philosophers Democritus and Epicurus held atomic theories of the universe"

social relation - a relation between living organisms (especially between people)