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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Glossary of chemistry terms | 11/20 | https://en.wikipedia.org/wiki/Glossary_of_chemistry_terms | reference | science, encyclopedia | 2026-05-05T07:59:20.572989+00:00 | kb-cron |
hydron (H+) Informally synonymous with proton. The cationic form of atomic hydrogen; i.e. a positively charged hydrogen nucleus of any isotopic composition. Thus the term can refer to a proton (11H+), deuteron (21H+), or triton (31H+).
hydrous Having or containing water molecules, referring especially to water of hydration. Contrast anhydrous.
hydroxide A diatomic anion consisting of a hydrogen atom covalently bonded to an oxygen atom, having an overall negative charge, with the chemical formula OH−; or any member of a class of organic and inorganic compounds containing a hydroxy group, e.g. sodium hydroxide (NaOH).
hydroxy
hygroscopy
== I ==
ideal gas A hypothetical gas composed of many randomly moving point particles that do not participate in any interparticle interactions, thereby making it mathematically convenient to describe and predict their behavior as state variables change. The ideal gas concept is useful because it obeys the ideal gas law and can be analyzed within the framework of statistical mechanics.
ideal gas constant Also universal gas constant. The proportionality constant in the ideal gas law, defined as 0.08206 L·atm/(K·mol).
ideal gas law Also general gas equation. The equation of state of a hypothetical ideal gas, which states that the volume of such a gas is proportional to the amount of gas and its Kelvin temperature, and inversely proportional to its pressure. The ideal gas law combines Boyle's law, Charles's law, Gay-Lussac's law, and Avogadro's law into a single equation, conventionally formulated as
P
V
=
n
R
T
{\displaystyle PV=nRT}
, where
R
{\displaystyle R}
is the ideal gas constant. The relationships between the state variables described in this equation are a good approximation of the behavior of many gases under a wide range of conditions, though there are some limitations.
ideal solution A solution for which the gas phase exhibits thermodynamic properties analogous to those of a mixture of ideal gases.
indicator A special compound added to a solution that changes color depending on the acidity of the solution. Different indicators have different colors and are effective within different pH ranges.
induced radioactivity Radioactivity caused by bombarding a stable isotope with elementary particles, forming an unstable, radioactive isotope.
inert (of a chemical species) Stable and chemically unreactive; or thermodynamically non-labile, decomposing at a slow or negligible rate. Examples of inert species include the noble gases, which are stable in their naturally occurring forms because their outermost electron shells are filled with as many electrons as possible, making them broadly resistant to the loss or gain of electrons.
inorganic compound Any chemical compound that does not contain carbon, though there are exceptions. Contrast organic compound.
inorganic chemistry The branch of chemistry concerning the chemical properties and reactions of inorganic compounds. Contrast organic chemistry.
insolubility The inability of a substance (the solute) to form a solution by being dissolved in another substance (the solvent); the opposite of solubility.
inspissation The process of thickening a liquid by any method of dehydration, especially evaporation.
insulator Any material that resists the flow of an electric current. Contrast conductor.
intensive property A physical quantity whose value does not depend on the size of the system or the quantity of matter for which it is measured. Examples include density, temperature, and pressure. Contrast extensive property.
interface The boundary between two spatial regions occupied by different matter, especially by matter in different phases or physical states. See also surface and phase boundary.
intermediate See reactive intermediate.
intermetallic A type of alloy that forms an ordered solid-state compound between two or more metallic elements. Intermetallics are generally hard and brittle, and have useful mechanical properties at high temperatures.
intermolecular force Any force that mediates interaction between molecules, e.g. electromagnetic forces of attraction or repulsion, hydrogen bonding, and the van der Waals force, all of which act between the atoms of one molecule and the atoms or ions of nearby molecules. Intermolecular forces are weak compared to intramolecular forces such as covalent bonds, which hold individual molecules together.
International System of Units (SI)
International Union of Pure and Applied Chemistry (IUPAC) An international federation of chemists that is recognized as the world authority in developing standards for chemical nomenclature and other methodologies in chemistry.
interstitial compound A compound composed of a transition metal bonded to either hydrogen, boron, carbon, or nitrogen, whose crystal structure consists of closely packed metal ions with the non-metal atoms located in the interstices.
intramolecular force
intrinsic property
ion A molecule that has gained or lost one or more electrons from its neutral state and therefore possesses a negative or positive electric charge.
ionic bond An electrostatic attraction between oppositely charged ions.
ionic strength A measure of the concentration of ions in a solution, usually expressed in terms of molarity (mol/L solution) or molality (mol/kg solvent).
ionization The breaking up of a chemical compound into separate ions.
isoelectronicity The phenomenon of two or more chemical species (atoms, molecules, ions, etc.) being composed of different elements but having the same number of valence electrons and the same structural arrangement (i.e. the same number of atoms with the same connectivity). Isoelectronic species typically show useful consistency and predictability in their chemical properties.
isomerization
isomers Ions or molecules with identical chemical formulas but distinct structures or spatial arrangements. Isomers do not necessarily share similar properties. The two main types of isomers are structural isomers and stereoisomers.
isotope A variant of a particular chemical element which differs in the number of neutrons present in the nucleus. All isotopes of a given element have the same number of protons in each atom.
== J ==
joule (J) The SI unit of energy (symbol: J). One joule is defined as one newton-metre.
== K ==
kelvin (K) The SI unit of temperature (symbol: K). The Kelvin scale is an absolute thermodynamic temperature scale that uses absolute zero as its null point.
keto acid Also ketoacid. Any organic compound that can be classified as both a ketone and a carboxylic acid, by virtue of containing a keto group and a carboxyl group.