Chemistry

Ester (organic functional group) Ester An ester is an organic functional group with the formula R–CO–OR′, formed from acids and alcohols; common in fats, fragrances, solvents and polyesters and identifiable by character…

Ethane: properties, production, uses and safety Ethane Ethane (C2H6) is a simple alkane gas used chiefly as a petrochemical feedstock. This article summarizes its structure, occurrence, industrial uses, hazards and historical context.

Ethanol (ethyl alcohol): properties, production, uses, and safety Ethanol Ethanol is a colorless, flammable alcohol used in beverages, solvents, fuels and antiseptics. This article explains its chemistry, production, history, common uses, and safety dist…

Ethylene (ethene): properties, production, and uses Ethylene Ethylene (ethene) is the simplest alkene: a high-volume industrial hydrocarbon used to make plastics, chemicals and as a plant hormone affecting ripening and growth.

Europium Europium is a soft, silvery rare-earth metal (atomic number 63) notable for its luminescent compounds, two common oxidation states (+2 and +3), and uses in phosphors, security inks…

Evaporating dish A shallow laboratory vessel used to evaporate solvents from solutions, concentrating solutes or recovering residues. Commonly ceramic or glass, it is designed for controlled heatin…

Evaporation: the process of liquids turning into vapor Evaporation Evaporation is the surface process by which molecules leave a liquid and enter the gas phase. This article explains how it works, factors that affect it, differences from boiling,…

Exothermic reaction An exothermic reaction releases energy, typically as heat, into its surroundings. This article covers definitions, thermodynamic basis, examples, measurement, history, applications…

Explosive material: properties, types, uses, and safety Explosive material A concise, neutral guide to explosive materials: what they are, how they differ, common examples and uses, historical development, and safety, transport and regulatory consideratio…

Extended periodic table and the search for superheavy elements Extended periodic table Overview of efforts to extend the periodic table beyond known elements, how new elements are made and detected, theoretical limits, the island of stability, and scientific signific…

Extracellular fluid: composition, compartments and clinical importance Extracellular fluid Extracellular fluid (ECF) surrounds cells and carries substances between organs. It includes plasma, interstitial fluid and transcellular fluid and makes up about one-third of tota…

Fatty acid: structure, types, biological roles, and notable facts Fatty acid Fatty acids are carboxylic acids with long hydrocarbon chains. This article explains their structure, types (saturated/unsaturated), biological roles as fuels and components of lip…

Fermium — synthetic actinide element (symbol Fm, atomic number 100) Fermium Fermium (Fm) is a synthetic, highly radioactive actinide with atomic number 100. It is produced in nuclear reactions and has no practical commercial uses; it is important mainly fo…

Ferric (iron in the +3 oxidation state) Ferric Ferric denotes iron in the +3 oxidation state (Fe3+). This article explains its chemistry, common compounds, uses, differences from ferrous iron, and safety and environmental notes…

Ferromanganese (Spiegeleisen): alloy of iron and manganese Ferromanganese Ferromanganese is an iron–manganese alloy used chiefly in steelmaking. This article explains its composition, production methods, historical role as spiegeleisen, industrial uses a…

Ferrous (iron-containing): definition, properties, and uses Ferrous Pertaining to iron or iron(II). Covers ferrous metals and compounds, terminology from Latin ferrum, industrial uses, corrosion and magnetic properties, and differences from non‑fer…

Fibreglass (glass-reinforced plastic) Fibreglass Fibreglass, or glass-reinforced plastic (GRP), is a fibre-reinforced polymer made from glass fibres embedded in a resin matrix. It is valued for light weight, corrosion resistance,…

Fire: Chemistry, Uses, Risks, and Historical Significance Fire Fire is a rapid oxidation process that releases heat and light. This article explains how fire works, its uses, hazards, historical role for humans, and key distinctions such as fl…

Fischer–Tropsch process Fischer-Tropsch process Catalytic chemical synthesis that converts synthesis gas (CO and H2) into liquid hydrocarbons and oxygenates; used in coal-, gas- and biomass-to-liquids routes and for specialty wa…

Flame (combustion): visible part of fire, structure, color, and uses Flame A flame is the visible, gaseous region produced by a combustion reaction. This article explains its structure, colors and temperatures, types, common uses, and safety consideration…

Flame retardant Substances and treatments that reduce the flammability of materials; overview of types, how they work, common uses, history, and safety considerations.

Flame test: qualitative identification of metal elements by color Flame test A flame test is a simple qualitative analysis in which heating a sample in a flame produces characteristic colors and spectral lines used to identify certain metal ions.

Flammability Flammability is the propensity of a material to ignite and sustain combustion; this article explains definitions, causes, tests, classifications, examples and safety considerations…

Flash point — flammability and safety of liquids Flash point Flash point is the lowest temperature at which a liquid produces enough vapor to ignite in air. This article explains what flash point means, how it is measured, classifications, f…

Laboratory flasks: types, design, and common uses Flask An overview of laboratory flasks: their shapes, materials, measurement conventions, common types, typical uses in chemistry and biology, and practical distinctions for laboratory w…

Flerovium (Element 114) Flerovium Flerovium (Fl, atomic number 114) is a synthetic, radioactive superheavy element produced in particle accelerators. It is of scientific interest for nuclear stability and relativis…

Florence flask: design, uses, history, and distinctions Florence flask A Florence flask is a round-bodied laboratory flask with a long neck used for boiling, heating, mixing and storing liquids. This article covers its design, materials, common uses a…

Flotation: Separation of Solids from Liquids by Gas Bubbles Flotation Flotation is a physico-chemical separation method that uses gas bubbles to lift particles from a liquid. It is widely used in mineral processing, wastewater treatment, and industri…

Fluoridation: Use of Fluoride in Water and Dental Care Fluoridation Fluoridation is the controlled addition of fluoride compounds to water or dental products to reduce tooth decay. It encompasses public health programs, topical treatments, benefits…

Fluoride (the fluoride ion) Fluoride Fluoride is the negatively charged ion of fluorine. It occurs in minerals, is used in dental care and water treatment, and has important chemical, medical and environmental conside…

Fluorine (element F) Fluorine Fluorine (F) is the most electronegative chemical element, atomic number 9 and atomic mass ≈19. A highly reactive, diatomic gas rarely found free in nature; its compounds are essen…

Fluorite: mineral form of calcium fluoride, properties, uses and history Fluorite Fluorite (CaF2) is a widespread mineral prized for its colors, fluorescence and industrial value as the principal source of fluorine. It is used in metallurgy, optics, chemicals an…

Foam: Structure, Formation, Types, and Uses Foam Foam is a dispersed material of gas bubbles separated by liquid or solid films. This article explains foam structure, formation, stability, types, common applications, and distinct…

Formaldehyde (Methanal) — properties, uses, and safety Formaldehyde Formaldehyde (methanal) is the simplest aldehyde: a colorless, pungent gas used in industry as an intermediate, disinfectant and resin precursor. It is reactive, widely produced, a…

Formic acid (methanoic acid): overview, properties, history and uses Formic acid Formic acid (methanoic acid) is the simplest carboxylic acid. This article covers its chemistry, natural occurrence, history, production, applications, safety and environmental rol…

Fractional distillation: principles, equipment, uses and industrial practice Fractional distillation Fractional distillation separates mixtures into components by exploiting differences in boiling points. This article explains how columns work, equipment, applications (especially…

Fractionating column (distillation device) Fractionating column A fractionating column is an apparatus used in chemistry and industry to separate components of a liquid mixture by repeated vaporization and condensation during fractional distill…

Francium (element 87) Francium Francium is a highly radioactive alkali metal (symbol Fr, Z=87), extremely rare on Earth and known mainly from brief-lived isotopes; discovered by Marguerite Perey in 1939 and used…

Free radical: reactive atoms and molecules in chemistry and biology Free radical Free radicals are atoms or molecules with unpaired electrons. They drive many chemical reactions, play roles in physiology and disease, and are balanced by antioxidant defenses and…

Freezing: the transition of liquids to solids — process, causes, and uses Freezing Freezing is the phase change in which a liquid becomes a solid. This article explains the physical mechanism, factors that affect freezing, common examples and applications, and no…

Freon: refrigerant family, chemistry, history and environmental issues Freon Freon is a trade name for several refrigerant gases (CFCs, HCFCs, HFCs and related compounds). This article explains its chemistry, uses, environmental impacts, regulation and mode…

Fructose: properties, natural sources, metabolism, and uses Fructose Fructose is a naturally occurring simple sugar found in fruits, honey and many vegetables; it has distinct chemistry and metabolic effects and is widely used as a sweetener in food…

Fuel: types, uses, history, and environmental impacts Fuel A fuel is a material that releases energy through chemical, nuclear or physical processes. This article explains fuel types, characteristics, history, common uses, and environmenta…

Fuel cell — electrochemical devices that generate electricity from fuels Fuel cell A fuel cell converts chemical energy from a fuel and an oxidant directly into electricity. This article explains how fuel cells work, their main types, fuel sources, applications,…

Fuel oil: types, production, uses, and environmental issues Fuel oil Liquid petroleum products used for heating or power generation, ranging from diesel and kerosene to heavy residual fuels; production, classifications, uses, safety and environmenta…

Fullerene (carbon cage molecule) Fullerene Fullerenes are hollow carbon molecules that form spheres, ellipsoids or tubes (buckyballs and nanotubes). Discovered in 1985, they are an allotrope of carbon with distinctive struc…

Fumaric acid: properties, occurrence, uses and history Fumaric acid Fumaric acid is a naturally occurring organic acid used as a food acidulant (E 297), in industry and in medicine; this article summarizes its chemistry, natural role, applications…

Fume hood: laboratory ventilation enclosure for hazardous vapors Fume hood A fume hood is a ventilated laboratory enclosure that captures and removes hazardous gases, vapors and aerosols. It reduces exposure, contains accidents, and comes in several desig…