Chemistry

Fumigation: Methods, Common Fumigants, Safety, History, and Uses Fumigation Fumigation uses gaseous toxicants to control pests in buildings, stored products and quarantine. This article outlines methods, common fumigants, safety steps, historical notes, ty…

Functional group (chemistry): definition, examples, and importance Functional group An overview of functional groups in organic chemistry: definition, common types, how they shape reactivity and properties, identification methods, historical context, and practical…

Fungicide: agents for controlling unwanted fungi Fungicide A fungicide is a chemical or biological agent that suppresses or destroys fungi. This article explains types, uses, environmental and safety considerations, resistance management,…

Fusion: joining, blending, and combined processes Fusion Fusion is the act or process of joining two or more things into one. The term applies across science, technology, culture and data — from nuclear reactions in stars to blended cuis…

Gadolinium: properties, history, uses and safety of the rare-earth metal Gadolinium Summary of gadolinium (Gd, atomic number 64): physical and chemical properties, occurrence, major applications (MRI contrast, phosphors, nuclear uses), and health and environmental…

Galactose: structure, metabolism, and biological role Galactose Galactose is a simple sugar related to glucose, commonly released from lactose digestion. This article covers its chemistry, occurrence, metabolic fate in the liver, biological fun…

Gallium: properties, occurrence, uses and notable characteristics Gallium Gallium (Ga, atomic number 31) is a soft, silvery metal with a low melting point. Widely used in semiconductors, LEDs, specialty alloys and research, it occurs only in trace amount…

Gallium arsenide — properties, structure, and applications Gallium arsenide Gallium arsenide (GaAs) is a III–V semiconductor with a direct bandgap. It is widely used in high-frequency electronics and optoelectronics, including LEDs, lasers, and solar cells…

Galvanizing: protective zinc coatings for corrosion control Galvanizing Galvanizing coats steel or iron with zinc to provide barrier and sacrificial protection. This article explains methods, benefits, applications, and practical distinctions between h…

Gamma‑Hydroxybutyric Acid (GHB): Properties, Uses, and Risks gamma-Hydroxybutyric acid GHB is a naturally occurring brain compound and a psychoactive drug. This article explains its chemistry, natural occurrence, medical uses, recreational use, legal status, and heal…

Garnet: mineral group, properties, varieties, and uses Garnet Garnet is a group of silicate minerals prized as gemstones and abrasives. This article summarizes its composition, crystal forms, varieties, geological occurrence, historical use,…

Gas: properties, types, behavior, and human uses Gas A gas is a state of matter whose particles move freely; this article explains properties, composition, examples, history, and practical uses of gases.

Gas chromatography: principles, instrumentation, and applications Gas chromatography Gas chromatography (GC) separates volatile mixtures by transporting a vaporized sample through a column with an inert carrier gas. This article explains how GC works, its component…

Gas chromatography–mass spectrometry (GC–MS): principles, instruments, and applications Gas chromatography–mass spectrometry GC–MS couples gas chromatographic separation with mass spectral identification to detect and quantify volatile and semi-volatile compounds across forensic, environmental, clinical,…

Gas syringe A laboratory instrument for collecting and measuring gases. Describes design, operation, typical uses (gas laws, reactions), advantages, limits, safety notes and related distinctio…

Gasoline (Petrol): Properties, Production, Uses, and Safety Gasoline Commonly called petrol, gasoline is a volatile petroleum-derived fuel used mainly in spark-ignition engines. This article explains composition, refining, grades, uses, safety and e…

Gasoline Fuel Additives: Types, Functions, and Engine & Environmental Impacts Gasoline additives Comprehensive guide to gasoline fuel additives—octane enhancers, detergents, corrosion inhibitors, lubricity agents, stabilizers and anti‑icing compounds—how they work, impacts on…

Gel (semi-solid colloidal material) Gel A gel is a semi-solid system in which a liquid is immobilized within a three-dimensional network, producing materials that are viscoelastic and widely used in food, medicine, and m…

Germanium (Ge): properties, history, and applications Germanium Germanium is a brittle, silver-gray metalloid (atomic number 32) valued for its semiconductor properties, infrared optics, and historical role in early transistors and audio effect…

Gibbs free energy Thermodynamic potential that predicts reaction spontaneity at constant pressure and temperature. Defined as G = H − T S; used across chemistry, physics, and engineering to assess e…

Glass: composition, types, history and practical uses Glass An accessible overview of glass: what it is, how it is made, major types and properties, historical development, common uses, recycling, and myths about its nature.

Glass rod Cylindrical glass tool used in laboratories and education for stirring, spreading liquids, electrostatic demonstrations and delicate manipulations; chosen for chemical resistance a…

Glass transition (Tg): the change from rigid to rubbery in amorphous materials Glass transition The glass transition is a reversible, temperature-dependent change in amorphous materials from a hard, brittle state to a softer, rubbery or viscous state. Key concepts, measuremen…

Glucose: a simple sugar, its structure, role in metabolism, and history Glucose Glucose is a six-carbon monosaccharide central to metabolism. This article explains its chemical nature, biological roles, production, clinical importance, and historical study.

Glue (adhesive): types, history, uses, and safety Glue An accessible overview of glue: what adhesives are, common natural and synthetic types, historical development, principal uses, and safety considerations.

Glutamic acid: properties, biological roles, and uses Glutamic acid Overview of glutamic acid (glutamate): chemistry, metabolic and neurotransmitter roles, umami taste and food uses (including MSG and E620–E625), production, safety, and physiologic…

Glycerol: properties, structure, history and common uses Glycerol Glycerol (glycerin) is a viscous, sweet-tasting trihydroxy alcohol (C3H8O3) used in foods, medicines, cosmetics, industry and as the backbone of many lipids.

Gold (Au): properties, history, uses, mining and notable facts Gold Gold is a dense, malleable yellow metal (Au, atomic number 79) valued as a precious metal. This article surveys its physical and chemical traits, history, common uses, mining metho…

Graduated cylinder (measuring cylinder) — design, uses and care Graduated cylinder A graduated cylinder is a common laboratory vessel for measuring liquid volumes. This article explains its parts, materials, accuracy, common uses, and care, and distinguishes it f…

Graphene: the two-dimensional form of carbon Graphene Graphene is a single-atom-thick sheet of carbon with a hexagonal lattice. It combines exceptional strength, conductivity and flexibility, and underpins advances in electronics, com…

Graphite (carbon allotrope) Graphite Graphite is a common allotrope of carbon with layered atomic structure; it is soft, electrically conductive, thermally stable and used in pencils, lubricants, electrodes, composite…

Green: appearance, physics, biology, and cultural significance Green Comprehensive overview of the colour green: its place in the visible spectrum, physical properties, role in plants, ways it is made in pigments and light, and cultural meanings.

Green chemistry: principles, history, disciplines and applications Green chemistry Green chemistry (sustainable chemistry) designs chemical products and processes to reduce hazards, waste, and energy use. It spans multiple disciplines and guides industry, policy,…

Grignard reaction — organomagnesium additions for carbon–carbon bond formation Grignard reaction A widely used organometallic method in organic synthesis: formation of organomagnesium reagents that add to electrophilic carbon centers to create C–C and C–heteroatom bonds.

Group (periodic table) A periodic table group is a vertical column whose members share outer‑electron counts and similar chemical behavior; this article explains their properties, common groups, history,…

Group 11 elements — copper, silver, gold and roentgenium (coinage metals) Group 11 element Group 11 comprises the coinage transition metals copper, silver and gold plus the synthetic element roentgenium. This article covers their properties, uses, history and notable dis…

Group 12 elements (zinc, cadmium, mercury, copernicium) Group 12 element Overview of Group 12 of the periodic table: members, electronic structure, physical and chemical properties, uses, occurrence, environmental and health considerations, and historic…

Group 14 (Carbon Group): properties, elements, and uses Group 14 element Overview of Group 14 of the periodic table: electronic structure, elemental members (C, Si, Ge, Sn, Pb), typical oxidation states, physical trends, occurrences and principal applic…

Group 16 (Chalcogens): Oxygen, Sulfur, Selenium, Tellurium, Polonium, Livermorium Group 16 element Group 16 of the periodic table — the chalcogens — contains oxygen, sulfur, selenium, tellurium, polonium and the synthetic livermorium. This article explains properties, history, u…

Group 3 (periodic table) Group 3 element Group 3 is a column of the periodic table containing scandium and yttrium plus two elements whose placement (lanthanum/actinium or lutetium/lawrencium) is debated.

Group transfer reaction A pericyclic process in which a sigma bond migrates as a pi bond is converted to a sigma bond; the ene reaction is the archetype with broad synthetic and mechanistic significance.

Guanine: a purine nucleobase in DNA and RNA Guanine Guanine is a purine nucleobase (C5H5N5O) found in DNA and RNA. It pairs with cytosine, forms G-quadruplexes, and is a component of nucleotides such as GTP with roles in energy tran…

Gunmetal (red brass): composition, properties, history and uses Gunmetal Gunmetal, a type of bronze often called red brass, is a copper‑based alloy prized for castability, corrosion resistance and bearing properties; historically used for cannons and ma…

Gunpowder (black powder): composition, history, and uses Gunpowder Gunpowder, or black powder, is an explosive mixture of saltpeter, charcoal, and sulfur. This article outlines its chemistry, how it works, historical development, common uses, and…

Gunshot residue (GSR): formation, detection, forensic use, and limitations Gunshot residue Gunshot residue (GSR) consists of particles produced when a firearm is discharged. This article explains its composition, sampling and analytical methods, forensic applications, pe…

Gypsum (calcium sulfate dihydrate): properties, uses, and varieties Gypsum Gypsum (CaSO4·2H2O) is a soft sulfate mineral used for plaster, drywall, cement control, and as a soil amendment. Overview of properties, formation, historical uses, and common var…

Haber process Industrial method for synthesizing ammonia from nitrogen and hydrogen using high pressure, elevated temperature and an iron catalyst; foundational for modern fertilizers and agricu…

Haem (heme): iron–porphyrin cofactors in biology Haem Haem (heme) is an iron-containing porphyrin cofactor found in haemoproteins such as haemoglobin, myoglobin and cytochromes. It mediates oxygen binding, electron transfer and cataly…