Chemistry
Articles about matter, substances, reactions and chemical science.
Halogen
Hard water
Hard water: causes, characteristics, effects and treatment
Hashish
Hashish: resin from the cannabis plant — composition, history, and uses
Hashish is a concentrated cannabis resin used historically and today for recreational and medicinal purposes; its composition, production methods, cultural history, and legal statu
Hassium
Hassium: a synthetic, highly radioactive transactinide element (Hs, Z=108)
Heat of combustion
Heavy metals
Heavy metals: definitions, properties, uses and environmental impact
Heavy water
Heavy water (deuterium oxide)
Helium
Helium — properties, occurrence, uses, and history
Helium is the light, inert noble gas with symbol He (atomic number 2). This article describes its properties, isotopes, origins, common uses, safety issues and notable low-temperat
Heptachlor
Heptane
Hexachlorobenzene
Hexachlorobenzene (HCB)
Hexadecene
Hexadecene (cetene): structure, isomers, properties and uses
Hexafluorosilicic acid
Hexafluorosilicic acid (H2SiF6)
Hexane
Holmium
Holmium (chemical element)
Homogeneity
Homogeneity: Meaning, Examples, and Importance Across Sciences
Homologous series
Homologous series (chemistry)
Household ammonia
Hückel's rule
Hückel's rule: aromaticity in cyclic conjugated systems
Hydration
Hydration (chemical hydrates)
Hydrazine
Hydrazoic acid
Hydrazoic acid (HN3): properties, preparation, uses and safety
Hydrazone
Hydrazone: structure, synthesis, reactions and applications
Hydride
Hydride (compounds of hydrogen with other elements)
Hydrobromic acid
Hydrobromic acid (HBr): properties, preparation, and uses
Hydrocarbon
Hydrocarbon: Chemistry, Types, Sources and Uses
Hydrochloric acid
Hydrochloric acid (HCl) — properties, production, uses, and safety
Hydrofluoric acid
Hydrofluoric acid (HF)
Hydrofluorocarbon
Hydrofluorocarbons (HFCs): chemistry, uses, and environmental effects
Hydrogen
Hydrogen: properties, isotopes, history, and common uses
Hydrogen atom
Hydrogen bond
Hydrogen bond: definition, mechanism, examples, and significance
Hydrogen bromide
Hydrogen bromide (HBr): properties, production, and uses
Hydrogen chloride
Hydrogen cyanide
Hydrogen cyanide (prussic acid)
Hydrogen deuteride
Hydrogen fluoride
Hydrogen fluoride (HF): properties, uses, and safety
Hydrogen halide
Hydrogen iodide
Hydrogen iodide (HI)
Hydrogen ion
Hydrogen ion (hydron): forms, properties, and significance
Hydrogen peroxide
Hydrogen peroxide (H2O2): properties, uses, and safety
Hydrogen selenide
Hydrogen selenide (H2Se)
Hydrogen sulfate
Hydrogen sulfate (bisulfate): the HSO4− ion — properties and uses
Hydrogen sulfide
Hydrogen sulfide (H2S): properties, occurrence, uses and hazards
Hydrogen telluride
Hydrogen telluride (H2Te)
Hydrogenation
Hydrogenation: adding hydrogen to unsaturated molecules
Hydrolysis
Hydrometer
Hydrometer: instrument for measuring liquid density and specific gravity