This page gathers the 10,116 dictionary entries belonging to the domain “Chemistry”, as labelled by Wiktionary. Each word leads to its full entry: definitions, etymology, pronunciation, examples. Page 46 of 101: from “homopolar” to “hydrogen peroxide”.
- homopolar adj Having symmetrically equal distribution of polarity; characterized by uniform electric or magnetic properties.
- homoserine noun The amino acid 2-amino-4-hydroxybutanoic acid that is an intermediate in the biosynthesis of methionine, threonine and isoleucine
- homospermine noun An analogue of spermine having an extra methylene group between the middle two nitrogen atoms; and derivative of this compound
- homosteroid noun A derivative of a steroid in which at least one carbon atom has been inserted to expand one of the four steroid rings.
- homotaurine noun A synthetic organic compound, analogous to taurine but with an extra carbon in its chain, potentially useful as an anticonvulsant and…
- homotropic adj related by an n-fold axis of rotation
- homovanillic acid noun A major catecholamine metabolite, used as a reagent to detect oxidative enzymes, and associated with dopamine levels in the brain
- honeycomb quartz noun A form of quartz exhibiting a pattern characterized by a hollow mesh of hexagonal or cellular formations, reminiscent of the natural…
- honokiol noun An organic compound (a dimer of allyl phenol) found in Magnolia grandifloris, used in traditional Japanese medicine as an as an anxiolytic…
- hopanoid noun Any of a class of pentacyclic compounds, somewhat similar to steroids, that have various functions in prokaryotes
- hormonal adj Pertaining to hormones.
- hornblende noun A green to black amphibole mineral, of complex structure, formed in the late stages of cooling in igneous rock.
- hotsonite noun A mineral containing aluminum, sulfur, oxygen, phosphorus and hydrogen originally found in South Africa.
- howieite noun A triclinic mineral containing aluminum, hydrogen, iron, magnesium, manganese, oxygen, silicon, and sodium.
- hox noun hypohalous acid
- hsianghualite noun An isometric-tetartoidal white mineral containing beryllium, calcium, fluorine, lithium, oxygen, and silicon.
- huangite noun A trigonal-hexagonal scalenohedral mineral containing aluminum, calcium, hydrogen, oxygen, and sulfur.
- hubeite noun A triclinic-pinacoidal mineral containing aluminum, calcium, hydrogen, iron, manganese, oxygen, and silicon.
- hübnerite noun A manganese tungstate mineral that forms reddish-brown to black monoclinic prismatic submetallic crystals.
- human chorionic gonadotropin noun A peptide hormone, produced during pregnancy, that prevents the breakdown of the corpus luteum and maintains progesterone production.
- humberstonite noun A trigonal-rhombohedral colorless mineral containing hydrogen, magnesium, nitrogen, oxygen, potassium, sodium, and sulfur.
- humite noun An orthorhombic-dipyramidal mineral containing fluorine, hydrogen, iron, magnesium, oxygen, and silicon.
- humulenol noun The sesquiterpenol (4Z,8Z)-6,6,9-trimethyl-2-methylidenecycloundeca-4,8-dien-1-ol derived from humulene
- huperzine noun Any of a family of sesquiterpenoid alkaloids, found in the firmoss Huperzia serrata, thought to aid memory.
- hyaline noun The main constituent of the walls of hydatid cysts; a nitrogenous body, which, by decomposition, yields a dextrogyrate sugar, susceptible…
- hyalomin noun Any of a family of immunoregulatory peptides obtained from the salivary glands of hard ticks of the genus Hyalomma
- hyalotekite noun A triclinic-pinacoidal mineral containing aluminum, barium, beryllium, boron, calcium, chlorine, copper, fluorine, iron, lead, magnesium…
- hyaluronic acid noun A mucopolysaccharide (a kind of polymer) that forms a gel-like substance within animal connective tissue.
- hybridization noun The linear combination of atomic orbitals in a molecule to form hybrid orbitals.
- hybridize verb To combine complementary subunits of multiple biological macromolecules.
- hydantoin noun The heterocycle imidazolidine-2,4-dione derived from urea and glycolic acid; any of its many derivatives
- hydnocarpic acid noun The unsaturated fatty acid 11-(2-cyclopenten-1-yl)undecanoic acid found in the oil of Hydnocarpus trees
- hydracid noun An acid that does not contain any oxygen; they are all binary compounds of hydrogen plus either a halogen (for example, hydrochloric acid…
- hydrate noun A solid compound containing or linked to water molecules.
- hydrated adj Combined chemically with water.
- hydration noun The incorporation of water molecules into a complex with those of another compound.
- hydrazide noun any compound derived from an oxoacid by replacing the hydroxide group with -NHNH₂ or derived forms -NRNR₂
- hydrazidine noun any compound derived from a carboxylic acid by replacing the carbonyl group with =NNH₂ and the hydroxyl group with -NHNH₂ (or substituted…
- hydrazination noun treatment or reaction with hydrazine, especially any addition reaction in which the elements of hydrazine are added across a double bond to…
- hydrazine noun A corrosive, fuming liquid, NH₂-NH₂, used as a rocket fuel.
- hydrazo noun The divalent radical and functional group -NHNH- derived from hydrazine, and N-substituted derivatives.
- hydrazone noun Any compound, of general formula R₂C=NNR₂, formally derived from an aldehyde or ketone by replacing the carbonyl group with =NNH₂ or…
- hydrazonic adj Describing any of several classes of oxyacids in which a double-bonded oxygen atom is replaced by a =N-NR₂ group.
- hydric adj Relating to hydrogen.
- hydricity noun The tendency in a transition metal hydride for an H⁻ ion to transfer to a substrate
- hydrido complex noun A complex hydride, such as sodium borohydride, containing a hydride ligand bonded to a central atom.
- hydrium noun hydrogen
- hydro- prefix hydrogen
- hydroacylation noun Any addition reaction in which an acyl group and a hydrogen atom (from an aldehyde) are added across a double bond
- hydroalkenylation noun Any addition reaction in which a hydrogen atom and an alkenyl group are attached across a double bond or triple bond
- hydroalkoxylation noun The addition reaction of an alcohol to a double bond in which a hydrogen atom is attached to one side and an alkoxy group to the other
- hydroalumination noun Any addition reaction in which atoms of hydrogen and aluminium are added across a double bond or triple bond
- hydroarylation noun Any addition reaction in which a hydrogen atom and an aryl group are attached across a double bond or triple bond
- hydroastrophyllite noun A triclinic-pinacoidal dark brown mineral containing aluminum, calcium, fluorine, hydrogen, iron, manganese, niobium, oxygen, potassium…
- hydroazidation noun Any addition reaction in which a hydrogen atom and an azide group are attached across a double bond or triple bond
- hydrobiotite noun A monoclinic-prismatic mineral containing aluminum, calcium, fluorine, hydrogen, iron, magnesium, oxygen, potassium, and silicon.
- hydroborate noun Any of several anions containing hydrogen bound to boron, especially the simplest one BH₄⁻; any salt or complex containing such an anion
- hydroborated adj reacted or treated with a hydroborate
- hydrobromic acid noun A solution of hydrogen bromide, HBr, in water; it is a strong acid, used in the production of bromine compounds.
- hydrobromide noun A compound of hydrobromic acid with an organic base (distinguished from a bromide, in which only the bromine unites with the base).
- hydrobromofluorocarbon noun Any halocarbon which contains hydrogen, bromine and fluorine; they are used as refrigerants, and have ODP (“ozone depleting potential”).
- hydrocarbonate noun bicarbonate
- hydrocarbostyril noun A nitrogenous hydrocarbon, C₉H₉NO, obtained from certain derivatives of cinnamic acid and closely related to quinoline and carbostyril.
- hydrocarboxylation noun The addition reaction of carbon monoxide and either water or an alcohol to the double bond of an olefin to produce a carboxylic acid or…
- hydrocarburet noun Carburetted hydrogen.
- hydrocarbylidene noun any divalent radical formed by removing two hydrogen atoms from the same carbon atom of a hydrocarbon, and the free valencies of which form…
- hydrocarbylidyne noun any divalent radical formed by removing three hydrogen atoms from the same carbon atom of a hydrocarbon, and the free valencies of which…
- hydrocerussite noun A form of lead carbondate, a trigonal-ditrigonal pyramidal mineral containing carbon, hydrogen, lead, and oxygen.
- hydrochloric acid noun A strong acid made by dissolving the gas hydrogen chloride in water. It reacts with alkalis, bases and many metals to form chlorides; it…
- hydrochlorofluorocarbon noun A man-made chemical compound containing hydrogen, chlorine, fluorine, and carbon, mainly used in refrigeration, air conditioning, foam…
- hydrochlorothiazide noun A diuretic drug, with the chemical formula C₇H₈ClN₃O₄S₂, that inhibits the kidneys' ability to retain water and lowers blood pressure.
- hydrocholeretic adj That increases the volume of secretion of bile from the liver without increasing the amount of solid matter secreted.
- hydrocracking noun The production of high-octane petroleum fuel and kerosene by hydrogenating large or complex hydrocarbons and then cracking them.
- hydrocyanation noun Any reaction in which the elements of hydrogen cyanide are added to a molecule, especially across a double bond.
- hydrocyanide noun A compound of hydrocyanic acid with a base, distinguished from cyanide, in which only the cyanogen so combines.
- hydrodechlorination noun The reductive dechlorination of organochlorine compounds (by the replacement of chlorine atoms by hydrogen)
- hydrodelhayelite noun An orthorhombic-pyramidal mineral containing aluminum, calcium, hydrogen, oxygen, potassium, and silicon.
- hydrodenitrification noun A chemical engineering process in which hydrotreating is used to reduce the nitrogen content of hydrocarbons during oil refining
- hydrodenitrogenation noun A chemical engineering process in which hydrotreating is used to reduce the nitrogen content of hydrocarbons during oil refining
- hydrodeoxygenation noun A chemical engineering process in which hydrotreating is used to reduce the oxygen content of hydrocarbons (present as alcohols, aldehydes…
- hydrodesulfurization noun a process for lowering the sulfur content of petroleum and similar products by catalytic hydrogenation, sulfur compounds being converted to…
- hydrodewaxing noun A chemical engineering process in which hydrotreating is used to reduce the wax content of hydrocarbons during oil refining
- hydrofining noun A chemical engineering process in which hydrocarbons are hydrogenated and desulfurized catalytically as part of oil refining
- hydrofluoric acid noun A solution of hydrogen fluoride, HF, in water; it is a weak but very corrosive acid, used in the production of fluorine compounds, and in…
- hydrofluoroalkane noun Any of various gaseous alkanes that contain carbon, fluorine, and hydrogen and are used especially as aerosol propellants in metered-dose…
- hydrofluoroether noun Any of a class of ethers (many of them polymeric) having a mixture of alkyl and fluorinated alkyl substituents
- hydroforming noun The reaction of petroleum with hydrogen
- hydrogen noun The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.008.
- hydrogen acid noun Any acid that contains at least one atom of hydrogen.
- hydrogen air noun An early term for hydrogen; hydrogen gas.
- hydrogen bond noun A weak bond in which a hydrogen atom in one molecule is attracted to an electronegative atom (usually nitrogen or oxygen) in the same or…
- hydrogen bromide noun A colourless gas having an irritating smell; it has the molecular formula HBr, and dissolves in water to form hydrobromic acid; it has many…
- hydrogen carbonate noun Synonym of bicarbonate.
- hydrogen cyanide noun A colourless, very poisonous, volatile liquid, HCN, used in the production of dyes, plastics and fumigants; it dissolves in water to form…
- hydrogen cycle noun the transmission of hydrogen from water to carbohydrates etc and back to water by living organisms
- hydrogen disulfide noun the sulfur analogue of hydrogen peroxide, H₂S₂
- hydrogen fluoride noun a colorless fuming liquid or gas, with molecular formula HF. It dissolves in water to form hydrofluoric acid and has many industrial uses…
- hydrogen iodide noun a colourless gas with molecular formula HI, having a suffocating smell; it forms hydriodic acid when dissolved in water
- hydrogen ion noun Used other than figuratively or idiomatically: see hydrogen, ion.: H⁻ or H⁺
- hydrogen peroxide noun A colourless liquid, H₂O₂, soluble in water, used as a mild antiseptic, bleaching agent (especially for bleaching hair), oxidizing agent…