Oxygen

Actinium oxide

A white solid isostructural with lanthanum oxide, underscoring how closely actinium's chemistry tracks that of its lanthanide neighbor despite sitting at the head of the actinide series.

Used for: Studied mainly to understand actinium's fundamental chemistry

Aluminum hydroxide

An amphoteric compound able to react as either an acid or a base, typically forming a gelatinous precipitate when made in water.

Used for: Antacid medication, flame retardant, water treatment

Aluminum oxide

An extremely hard, high-melting ionic oxide found naturally as corundum, the mineral behind ruby and sapphire gemstones.

Used for: Abrasives, refractory ceramics, primary ore for aluminum metal

Aluminum sulfate

An ionic salt that hydrolyzes in water to give a mildly acidic solution, historically combined with a second sulfate to form alum.

Used for: Water treatment flocculant, paper sizing, soil pH control

Americium dioxide

A black solid with the fluorite structure typical of tetravalent actinide oxides, formed by heating americium compounds in oxygen. It's the most stable oxide form of americium under ambient conditions.

Used for: Encapsulated radiation source in ionization-type smoke detectors

Americium(III) oxide

A reddish-brown solid holding americium in the +3 state, its most stable oxidation state in aqueous solution and solid compounds alike. It forms when americium dioxide is heated under reducing conditions.

Ammonium heptamolybdate

A white, water-soluble salt that is the most common commercial form of molybdenum, widely used as an analytical reagent and micronutrient fertilizer.

Used for: Micronutrient fertilizer and reagent for detecting phosphate in analytical chemistry

Ammonium metavanadate

A pale yellow-white crystalline salt that is the standard commercial starting material for manufacturing other vanadium compounds, since it decomposes cleanly to vanadium oxides on heating.

Used for: Industrial precursor for vanadium pentoxide and vanadium catalysts

Ammonium perrhenate

A white, water-soluble crystalline salt that is the main commercial form in which rhenium is sold and shipped, since it is easily purified from ore-processing streams.

Used for: Primary industrial source material for producing rhenium metal and its alloys

Antimony trioxide

A white powder and antimony's most important commercial compound, prized as a synergist that boosts the effectiveness of halogenated flame retardants.

Used for: Flame-retardant synergist in plastics and textiles

Arsenic trioxide

A white, odorless solid also known as white arsenic, existing as molecular As4O6 units in its common crystalline form. It's the most common commercial arsenic compound and highly toxic even in small doses.

Used for: Historic rodenticide and wood preservative; now a leukemia treatment

Barium carbonate

A dense white powder, also found naturally as the mineral witherite, once widely used as a rodenticide because it dissolves in stomach acid but not in water.

Used for: Rat poison and ingredient in specialty ceramic glazes and optical glass

Barium hydroxide

A strong alkaline base, sometimes called baryta, used in analytical chemistry to titrate weak acids because its solutions stay clear of carbonate interference.

Used for: Standard base for titrating weak organic acids in analytical chemistry

Barium nitrate

A colorless, water-soluble oxidizer that burns with a vivid green flame, making it a mainstay of pyrotechnic formulations.

Used for: Green color agent and oxidizer in fireworks and flares

Barium sulfate

An extremely insoluble white solid, safe to ingest despite barium's toxicity because it passes through the body unabsorbed — exactly why it works as a contrast agent.

Used for: Radiocontrast agent for gastrointestinal X-ray imaging

Berkelium dioxide

A dark brown solid with the fluorite structure common to tetravalent actinide oxides, and one of only a handful of berkelium compounds ever isolated and characterized. It has been produced and studied only in microgram amounts.

Beryl

A ring-silicate mineral whose color comes from trace impurities: chromium or vanadium produces emerald, while iron produces aquamarine.

Used for: Gemstone (emerald, aquamarine), primary ore of beryllium

Beryllium oxide

A hard, white ceramic oxide notable for combining electrical insulation with unusually high thermal conductivity for a non-metal.

Used for: Ceramic insulator in electronics and heat sinks

Bismuth oxychloride

A pearly white powder built from stacked layers that scatter light with a soft, nacre-like shimmer, giving it an optical effect similar to ground mother-of-pearl.

Used for: Pearlescent shimmer pigment in cosmetics such as eyeshadow and foundation

Bismuth subsalicylate

A pale yellow, water-insoluble organobismuth compound that coats and soothes the stomach lining while its salicylate portion provides mild anti-inflammatory action.

Used for: Active ingredient in over-the-counter upset-stomach remedies like Pepto-Bismol

Bismuth trioxide

A pale yellow solid and the most important commercial bismuth compound, serving as the starting point from which nearly all other bismuth chemicals are produced.

Used for: Precursor for bismuth chemicals and ingredient in ceramic glazes and electroceramics

Borax

A hydrated sodium borate mineral built from linked boron-oxygen rings, crystallizing naturally as soft, colorless crystals in dry lakebeds.

Used for: Laundry booster, metalworking flux, glass and ceramic glazes

Boric acid

A weak acid made of flat, triangular molecules that stack together through hydrogen bonding into soft, flaky white crystals.

Used for: Antiseptic, insecticide, eye-wash solutions, glass manufacturing

Boron trioxide

A glass-forming oxide that readily solidifies into an amorphous network rather than an ordered crystal lattice.

Used for: Key ingredient in borosilicate glass and fiberglass

Cadmium oxide

A brownish-black crystalline oxide that forms when cadmium metal burns in air. It behaves as a wide-bandgap semiconductor as well as an industrial chemical intermediate.

Used for: Electroplating baths and nickel-cadmium battery electrodes

Calcium carbonate

An ionic carbonate salt found naturally as limestone, chalk, and marble, and as the structural material of seashells and coral.

Used for: Antacid tablets, cement and construction, calcium supplement

Calcium phosphate

An ionic salt that, in its hydroxyapatite form, makes up the mineral structure of bones and teeth.

Used for: Fertilizer, dietary supplement, food additive

Californium dioxide

A black oxide representing californium's less common +4 oxidation state, identified alongside the more stable sesquioxide in trace laboratory samples. Characterizing it required some of the only californium ever produced in isolable quantities.

Carbon dioxide

A linear molecule produced by respiration and combustion, and the main greenhouse gas driving global climate change.

Used for: Carbonating beverages, fire extinguishers, dry ice refrigeration

Carbon monoxide

A colorless, odorless gas held together by a strong triple bond, formed from incomplete combustion and dangerous because it binds hemoglobin far more tightly than oxygen does.

Used for: Industrial reducing agent in metal smelting, syngas feedstock

Ceric ammonium nitrate

An orange-red crystalline salt and one of chemistry's most reliable single-electron oxidants, widely known simply as CAN in organic synthesis labs.

Used for: Oxidizing reagent in organic synthesis and printed-circuit etching

Cerium(III) oxide

A blue-green oxide that readily picks up oxygen from air to become cerium(IV) oxide, illustrating how easily cerium swings between its two common oxidation states.

Used for: Precursor in cerium oxide production and glass-polishing formulations

Cerium(IV) oxide

A pale yellow oxide, also called ceria, that showcases cerium's unusually accessible +4 state and its knack for shuttling oxygen atoms in and out of its crystal lattice.

Used for: Catalytic converter component and glass/optical-lens polishing compound

Cerium(IV) sulfate

A yellow-orange oxidizing salt, also called ceric sulfate, whose precisely standardized solutions are a workhorse titrant in analytical chemistry.

Used for: Oxidimetric titrant in analytical chemistry (cerimetry)

Cesium carbonate

A hygroscopic white salt widely used as a mild, highly soluble base in organic and pharmaceutical synthesis.

Used for: Base reagent in organic synthesis, including palladium-catalyzed couplings

Cesium hydroxide

The strongest of the common alkali metal hydroxides, a highly corrosive, deliquescent solid that dissolves readily in water.

Used for: Strong base used in specialty batteries and research chemistry

Chromium(III) oxide

A stable, hard green solid representing chromium's common +3 oxidation state. Its intense color and chemical inertness have made it one of the longest-used green pigments in industry.

Used for: Green pigment for paints, ceramics, and glass; abrasive polishing compound

Chromium(VI) oxide

A dark red, highly reactive solid featuring chromium in its +6 state. It dissolves in water to form chromic acid, a powerful oxidizer that is far more aggressive than chromium's more common +3 compounds.

Used for: Industrial chromium electroplating and metal-finishing baths

Cobalt blue

A vividly blue spinel-structured pigment formed by firing cobalt(II) and aluminum oxides together. It has been prized for centuries for its rich, stable color in art and ceramics.

Used for: Blue pigment in paints, ceramics, and glass

Cobalt(II,III) oxide

A black spinel-structured oxide that combines cobalt in both the +2 and +3 oxidation states within one crystal lattice, giving it useful magnetic and catalytic behavior.

Used for: Ceramic pigment and electrode material studied for lithium-ion batteries

Cobalt(II) sulfate

A reddish crystalline salt (in its common hydrated form) that provides a water-soluble source of cobalt ions for industrial and agricultural applications.

Used for: Electroplating baths and trace-mineral additive in animal feed

Copper(I) oxide

A red solid found in nature as the mineral cuprite, formed from copper's less common +1 oxidation state. It has long served as both a pigment and a protective coating additive.

Used for: Antifouling paint for ship hulls and red ceramic glaze pigment

Copper(II) oxide

A black solid representing copper's more common +2 oxidation state, formed readily when copper metal is heated in air and widely used to color glass and glazes.

Used for: Pigment in ceramics and glass; precursor in copper chemical manufacturing

Copper(II) sulfate

Best known in its vivid blue pentahydrate form ("blue vitriol"), this is perhaps the most recognizable copper compound, prized for its striking color and long history in classic chemistry demonstrations.

Used for: Fungicide and algicide (Bordeaux mixture) and copper electroplating

Curium dioxide

A black, fluorite-structured oxide representing curium's less common +4 oxidation state, prepared by igniting curium compounds in oxygen. It converts to the more stable sesquioxide on further heating.

Curium sesquioxide

A tan-to-white solid holding curium in its dominant +3 oxidation state, the more thermodynamically stable of curium's two well-characterized oxides. It has been made and studied only in milligram quantities because of curium's intense radioactivity.

Dysprosium(III) oxide

A white, highly magnetic rare-earth oxide and the standard commercial form of dysprosium, valued for its strong response to magnetic fields even among the lanthanides.

Used for: Precursor for dysprosium additives in high-strength neodymium magnets

Erbium(III) oxide

A distinctive pink rare-earth oxide, the standard commercial source of erbium, prized as a colorant precisely because of its strong pink tint.

Used for: Pink colorant in glass and ceramic glazes, and cubic zirconia gemstones

Ethanol

A simple alcohol whose polar hydroxyl group lets it mix freely with water while its hydrocarbon chain keeps it flammable and volatile.

Used for: Alcoholic beverages, fuel additive, disinfectant and solvent

Europium(III) oxide

A pale pink to white rare-earth oxide that is the most common commercial source of europium and serves as the parent compound for europium-activated phosphors.

Used for: Base material for red phosphors in older CRT and plasma displays

Gadolinium(III) oxide

A white, high-melting rare-earth oxide that is the standard commercial form of gadolinium and a common host lattice for phosphor and ceramic applications.

Used for: Starting material for gadolinium-based MRI contrast agent compounds

Germanium dioxide

A white crystalline solid also called germania, structurally similar to silica with germanium bonded to oxygen in a tetrahedral network. It's the main industrial source of purified germanium metal.

Used for: Doping agent for optical fiber cores

Glucose

A six-carbon simple sugar that exists mainly as a ring-shaped molecule in solution, and the primary energy source for most living cells.

Used for: Cellular energy metabolism, IV fluids, food and beverage sweetening

Gold(III) oxide

A dark brown, thermally unstable oxide that breaks back down into elemental gold and oxygen on heating, reflecting gold's general reluctance to bond strongly with oxygen.

Used for: Occasional precursor in gold nanoparticle and thin-film research

Hafnium dioxide

A hard, chemically inert white oxide with an unusually high dielectric constant, which let it replace silicon dioxide as the insulating layer in modern transistor gates.

Used for: High-k gate dielectric in advanced semiconductor transistors

Holmium(III) oxide

A pale yellow rare-earth oxide known for its extremely sharp optical absorption bands, which make holmium-doped glass a standard reference for calibrating spectrophotometers.

Used for: Wavelength calibration standard in optical spectroscopy instruments

Hydrogen peroxide

A molecule built around an unstable oxygen-oxygen single bond, making it a strong oxidizer that slowly decomposes into water and oxygen gas.

Used for: Antiseptic and disinfectant, hair bleaching, rocket oxidizer

Indium(III) oxide

A pale yellow oxide and indium's main commercial form, valued for the transparent, conductive thin films it forms when doped with a small amount of tin.

Used for: Precursor for transparent conductive coatings on touchscreens and displays

Indium(III) sulfate

A white, water-soluble indium salt used mainly as a bath component for depositing bright indium coatings by electroplating.

Used for: Electrolyte in indium electroplating baths

Iridium(IV) oxide

A blue-black oxide with a rutile-type crystal structure that, unusually for a simple metal oxide, conducts electricity almost like a metal.

Used for: Electrode coatings for chlorine production and water electrolysis

Iron(III) oxide

A reddish-brown ionic oxide that forms when iron corrodes in the presence of oxygen and moisture, commonly known as rust.

Used for: Pigment in paints, polishing compound, iron ore for steelmaking

Lanthanum carbonate

An insoluble lanthanum salt taken orally to bind excess dietary phosphate in the gut, passing through the digestive tract largely unabsorbed.

Used for: Phosphate-binding medication for kidney dialysis patients

Lanthanum oxide

A white, air-stable oxide and lanthanum's standard commercial form, used to fine-tune the refractive index of specialty optical glass.

Used for: Component of high-refractive-index camera and telescope lens glass

Lead(II,IV) oxide

Known as red lead, a bright orange-red mixed-valence oxide that combines lead in both the +2 and +4 states within one crystal structure.

Used for: Anti-corrosive primer pigment for steel structures and ships

Lead(II) oxide

Known as litharge in its red tetragonal form and massicot in its yellow orthorhombic form, this oxide is the starting material for most other lead compounds made industrially.

Used for: Flux in leaded crystal glass and ceramic glazes, and paste for lead-acid battery plates

Lead(II) sulfate

A white, nearly insoluble salt known naturally as the mineral anglesite, and the compound that coats both plates of a lead-acid battery once it has been discharged.

Used for: Forms on lead-acid battery electrodes during discharge

Lead(IV) oxide

A dark brown, strongly oxidizing solid in which lead reaches its less common +4 state, giving the compound enough oxidizing power to serve as a battery electrode material.

Used for: Positive-plate active material in lead-acid car batteries

Lithium carbonate

A white ionic salt that is one of the few practical sources of soluble lithium ions, produced from lithium-bearing brines and minerals.

Used for: Mood-stabilizing medication for bipolar disorder

Lithium hydroxide

A strong alkaline compound that absorbs carbon dioxide efficiently for its weight, and a key precursor in manufacturing lithium-ion battery cathodes.

Used for: CO2 scrubbing in submarines and spacecraft, battery material production

Lithium niobate

A synthetic crystal with strong piezoelectric and nonlinear-optical properties, grown in large single crystals for use throughout the electronics and photonics industries.

Used for: Surface acoustic wave filters in phones and optical modulators in telecom equipment

Lutetium oxyorthosilicate

A dense synthetic crystal, usually grown with a small amount of cerium doping, that converts incoming gamma rays into flashes of visible light extremely quickly.

Used for: Scintillator crystal in PET scanner detectors

Lutetium(III) oxide

A white, dense rare-earth oxide and the standard commercial form of lutetium, the heaviest and densest of the naturally occurring lanthanides.

Used for: Precursor for lutetium-based scintillator crystals used in medical imaging

Magnesium hydroxide

A weak, poorly soluble base that forms a milky suspension in water, giving rise to its common name.

Used for: Antacid and laxative (milk of magnesia), flame retardant filler

Magnesium oxide

An ionic oxide with a very high melting point, known in its mineral form as magnesia.

Used for: Refractory furnace linings, antacid and laxative, dietary supplement

Magnesium sulfate

An ionic salt best known in its hydrated form, Epsom salt, which dissolves readily in water to give a bitter-tasting solution.

Used for: Epsom salt baths, soil magnesium supplement, medical treatment

Malachite

A bright green basic copper carbonate mineral that forms naturally where copper ores weather, and is the same compound responsible for the green patina that develops on aged copper and bronze.

Used for: Ornamental stone and green pigment; ore of copper

Mercury(II) oxide

A dense red or yellow solid depending on particle size, formed by heating mercury in air or by precipitation, and one of the few oxides that decomposes back into its elements on strong heating.

Used for: Electrode material in older mercury button-cell batteries

Molybdenum hexacarbonyl

A white, volatile solid in which a molybdenum atom is surrounded octahedrally by six carbon monoxide ligands, a classic and widely studied organometallic compound.

Used for: Catalyst and vapor-deposition precursor for depositing molybdenum films

Molybdenum trioxide

A pale yellow solid formed by roasting molybdenite ore, and the principal industrial intermediate for producing molybdenum metal and other molybdenum chemicals.

Used for: Precursor for molybdenum metal and catalysts; glass and pigment colorant

Neodymium oxide

A pale blue-lavender, air-stable oxide and neodymium's standard commercial form, used to tint glass and ceramics a distinctive violet-to-red hue.

Used for: Colorant for glass and ceramics; precursor for neodymium metal

Neptunium dioxide

A brownish-green solid sharing the fluorite structure of uranium dioxide, and the most stable and best-characterized neptunium compound known. It forms readily when neptunium metal or its salts are heated in air.

Used for: Standard chemical form for storing and studying neptunium

Nickel(II) hydroxide

A pale green solid that acts as the active positive-electrode material in several rechargeable battery chemistries, cycling between nickel(II) and nickel(III) states as the battery charges and discharges.

Used for: Positive electrode material in nickel-cadmium and nickel-metal hydride batteries

Nickel(II) oxide

A green-black solid formed by nickel's stable +2 oxidation state, used both as a coloring agent and as a starting material for producing metallic nickel and other nickel compounds.

Used for: Ceramic glazes and precursor for nickel-metal hydride battery electrodes

Nickel(II) sulfate

A blue-green crystalline salt that is the primary nickel source used in electroplating baths, valued for its high solubility and consistent nickel(II) ion supply.

Used for: Nickel electroplating

Niobium pentoxide

A white, chemically stable oxide and the starting material for nearly all commercial niobium chemicals, valued for its high refractive index.

Used for: High-refractive-index component in camera lens glass and capacitor dielectrics

Nitric acid

A strong, highly corrosive oxidizing acid that slowly decomposes in light, turning older samples faintly yellow.

Used for: Fertilizer and explosives manufacturing, metal etching

Nitrogen dioxide

A reddish-brown, sharp-smelling gas that exists in equilibrium with its colorless dimer, N2O4, and is a major contributor to urban smog.

Used for: Component of vehicle exhaust and smog, nitric acid production

Nitrous oxide

A linear, sweet-smelling gas nicknamed laughing gas for the mild anesthetic and euphoric effects it produces when inhaled.

Used for: Dental and medical anesthetic, aerosol propellant, engine power boost

Osmium dioxide

A black, chemically inert solid with a metallic-like electrical conductivity, formed when osmium sits in its intermediate +4 oxidation state.

Used for: Laboratory intermediate in osmium refining and research chemistry

Osmium tetroxide

A pale yellow, volatile solid with a sharp odor and notoriously toxic vapor, famous for reacting readily with carbon-carbon double bonds.

Used for: Staining agent for lipids in electron microscopy and reagent for alkene dihydroxylation

Ozone

A bent, triatomic allotrope of oxygen that is a strong oxidizer, unstable at ground level but essential as a UV-absorbing layer in the stratosphere.

Used for: Stratospheric UV shielding, water disinfection, air purification

Palladium(II) acetate

An orange-brown, soluble palladium salt that is one of the most widely used catalysts in modern organic chemistry, central to many carbon-carbon bond-forming reactions.

Used for: Catalyst for Heck, Suzuki, and other palladium-catalyzed cross-coupling reactions

Palladium(II) nitrate

A water-soluble palladium salt commonly supplied as a dilute solution, used as a convenient soluble palladium source for catalyst preparation and plating.

Used for: Soluble palladium source for catalyst impregnation and plating solutions

Palladium(II) oxide

A black solid formed when palladium metal is heated in oxygen, used as a catalyst and as an intermediate in recovering palladium from spent catalytic materials.

Used for: Catalyst in oxidation reactions and hydrogenation catalyst precursor

Phosphoric acid

A triprotic acid built around a central phosphorus atom bonded to four oxygens, moderately strong and notably non-volatile.

Used for: Soft drink acidity/flavoring, fertilizer production, rust removal

Phosphorus pentoxide

A molecular oxide built from four phosphorus atoms linked through oxygen bridges into a cage-like structure, and one of the most powerful common drying agents.

Used for: Dehydrating agent, precursor to phosphoric acid

Platinum(IV) oxide

A dark brown powder known commercially as Adams' catalyst, which is reduced in situ to finely divided platinum metal to drive hydrogenation reactions.

Used for: Catalyst for hydrogenating alkenes, alkynes, and other unsaturated groups

Plutonium dioxide

A dense, stable ceramic solid with a fluorite structure, the most common and chemically robust form in which plutonium is stored and handled. It resists further oxidation and dissolves only slowly in most acids.

Used for: Fuel component in mixed-oxide (MOX) reactor fuel and radioisotope power sources

Polonium dioxide

A yellow (low-temperature) or black (high-temperature) solid formed by heating polonium metal in oxygen, and one of the small handful of polonium compounds characterized in any detail, owing to how little polonium exists to study at once.

Used for: Studied mainly for fundamental research into polonium's chemistry

Potassium dichromate

A bright orange crystalline salt and one of the most recognizable chromium(VI) compounds, prized in classical chemistry for its strong, reliable oxidizing power in acidic solution.

Used for: Oxidizing agent in redox titrations and historically in leather tanning

Potassium hydroxide

A strong, highly caustic alkali that dissolves readily in water and absorbs moisture from air. It's the potassium counterpart to sodium hydroxide (lye).

Used for: Manufacturing liquid soaps, batteries, and biodiesel

Potassium nitrate

Also known as saltpeter, this ionic salt forms colorless crystals and acts as a strong oxidizer when heated. It occurs naturally as efflorescent deposits in soil and caves.

Used for: Traditional ingredient in gunpowder and a common fertilizer

Potassium permanganate

A deep purple crystalline salt that acts as a strong oxidizing agent, staining almost anything it touches. Its color comes from manganese sitting in its +7 oxidation state.

Used for: Water treatment, wound disinfection, and wilderness fire-starting

Praseodymium oxide

A dark brown-black mixed-valence oxide, the stable form praseodymium metal adopts on exposure to air, prized for producing a distinctive yellow color in glass and ceramics.

Used for: Yellow colorant in glass, enamel, and ceramic glazes

Promethium(III) oxide

A rare, faintly pink-tinged oxide of one of the only entirely synthetic, intensely radioactive lanthanides, made in milligram quantities for research rather than everyday use.

Used for: Research-scale compound; the element itself has seen use in tritium-free luminous devices

Protactinium pentoxide

A white solid and the most stable, best-studied protactinium compound, formed by igniting protactinium salts in air and used as the reference point for calculating the element's atomic weight.

Used for: Reference compound in protactinium research; precursor to protactinium metal

Radium sulfate

An extremely insoluble salt that closely mirrors barium sulfate in structure and behavior, which is why trace radium co-precipitates with barite and other barium sulfate minerals in nature.

Used for: Explains radium's natural association with barium-bearing ores

Rhenium dioxide

A dark brown to bluish-black, chemically inert solid in which rhenium sits in its intermediate +4 oxidation state.

Used for: Laboratory intermediate in rhenium refining and catalyst preparation

Rhenium heptoxide

A pale yellow, volatile solid and the most stable oxide of rhenium, reflecting rhenium's most common and highest, +7, oxidation state.

Used for: Starting material for making other rhenium(VII) compounds and catalysts

Rhodium(III) nitrate

A red, water-soluble salt used as a soluble source of rhodium ion in catalyst preparation and electroplating solutions.

Used for: Rhodium source in electroplating baths and catalyst synthesis

Rhodium(III) oxide

A gray-black oxide formed when rhodium metal is heated in air or oxygen, used mainly as an intermediate in refining and recovering rhodium.

Used for: Intermediate in rhodium refining and catalyst manufacturing

Rubidium carbonate

A hygroscopic white salt used chiefly as a starting material for other rubidium compounds and in specialty high-index optical glass.

Used for: Additive in high-refractive-index optical glass and fiber optics

Rubidium hydroxide

A strongly corrosive, highly water-soluble alkali hydroxide, among the strongest bases known due to rubidium's large, weakly polarizing cation.

Used for: Electrolyte component in some specialty batteries

Rubidium nitrate

A white crystalline oxidizer salt used mainly as a laboratory source of rubidium ion and in some specialty pyrotechnic formulations.

Used for: Pyrotechnics and specialty glass and ceramics

Ruthenium dioxide

A dark, electrically conductive oxide used as a coating on titanium electrodes because it resists corrosion while efficiently catalyzing chlorine and oxygen evolution.

Used for: Coating on dimensionally stable anodes for the chlor-alkali and electroplating industries

Ruthenium tetroxide

A pale yellow, highly volatile and powerfully oxidizing solid, among the strongest oxidizers used in organic chemistry, requiring careful handling because it can explode.

Used for: Strong oxidant for cleaving alkenes and staining samples for electron microscopy

Samarium(III) oxide

A pale yellow rare-earth oxide formed when samarium metal is burned or its salts are calcined; like other lanthanide sesquioxides it adopts an ionic Sm3+/O2- lattice.

Used for: Infrared-absorbing optical glass and ceramic capacitor additives

Scandium oxide

A white, high-melting-point oxide, the most common commercially available scandium compound, formed by scandium's single stable +3 oxidation state.

Used for: Specialty ceramics, doping component in some solid-oxide fuel cells

Selenium dioxide

A white to pale yellow solid and the most common laboratory selenium compound, readily formed by burning selenium in air and dissolving in water to give selenous acid.

Used for: Oxidizing agent in organic synthesis and catalyst for selective allylic oxidation

Selenous acid

A weak, water-soluble acid formed when selenium dioxide dissolves in water, serving as the parent compound for selenite salts.

Used for: Precursor for selenite compounds and a bluing agent in gun-metal finishing

Silicon dioxide

A covalent network solid built from linked SiO4 tetrahedra, forming quartz crystals when ordered or ordinary glass when disordered.

Used for: Glassmaking, construction sand, silicon chip manufacturing

Silver nitrate

A water-soluble silver salt made by dissolving silver metal in nitric acid. It darkens on exposure to light or organic matter as it slowly decomposes to metallic silver, and serves as the main starting point for making most other silver compounds.

Used for: Photographic film, silver plating, and medical antiseptics

Silver oxide

A dark brown-black solid formed when silver ions react with hydroxide in solution. It is mildly basic and breaks back down into metallic silver and oxygen gas when heated.

Used for: Positive electrode material in silver-oxide button-cell batteries

Sodium bicarbonate

A mildly alkaline ionic salt known as baking soda, which releases carbon dioxide gas when it reacts with acids or heat.

Used for: Baking leavening agent, antacid, fire extinguisher and cleaning agent

Sodium carbonate

An alkaline ionic salt known as soda ash or washing soda, historically extracted from the ashes of certain plants.

Used for: Glass manufacturing, water softening, laundry detergent

Sodium hydroxide

A strong ionic base known as lye or caustic soda, highly corrosive and extremely soluble in water.

Used for: Soap and paper manufacturing, drain cleaner, industrial pH control

Sodium hypochlorite

The sodium salt of hypochlorous acid, sold as a pale yellow-green aqueous solution. It's a strong oxidizer that breaks down pigments and destroys microorganisms.

Used for: Active ingredient in household bleach and water disinfection

Sodium molybdate

A white, water-soluble salt used as a convenient soluble source of molybdenum in agriculture and as a corrosion inhibitor.

Used for: Trace-element fertilizer additive and corrosion inhibitor in cooling systems

Sodium pertechnetate

A water-soluble salt containing technetium-99m that is eluted directly from hospital technetium generators and injected as the workhorse radioactive tracer of nuclear medicine.

Used for: Most widely used radioactive tracer for diagnostic imaging (thyroid and bone scans)

Sodium phosphate

An alkaline ionic salt of phosphoric acid, sold as trisodium phosphate for its strong grease-cutting cleaning power.

Used for: Heavy-duty cleaning agent, food additive, water treatment

Sodium selenite

A white crystalline salt that is the most common source of dietary selenium supplementation, dissolving readily to deliver selenium in a bioavailable form.

Used for: Selenium supplement in animal feed and multivitamins

Sodium silicate

A soluble silicate salt made by fusing sand with sodium carbonate, sold as a thick, syrupy solution commonly called water glass.

Used for: Adhesives, detergent builder, egg preservation

Sodium sulfate

An ionic salt known historically as Glauber's salt in its hydrated form, colorless and highly soluble in water.

Used for: Detergent filler, glass and paper manufacturing, textile dyeing

Strontium carbonate

A white, poorly water-soluble compound found naturally as the mineral strontianite, once the key ingredient in red phosphors and color television glass.

Used for: Ceramic ferrite magnets and pyrotechnic red colorant

Strontium nitrate

A colorless, water-soluble oxidizing salt best known for producing the brilliant red flares seen in fireworks and road signal flares.

Used for: Red colorant and oxidizer in fireworks and signal flares

Strontium oxide

A caustic white solid, sometimes called strontia, that reacts vigorously with water to form strontium hydroxide.

Used for: Additive in specialty glass and ceramic glazes

Strontium sulfate

A sparingly soluble white mineral known as celestine, the principal natural ore from which strontium metal and its compounds are extracted.

Used for: Primary commercial ore of strontium

Sulfur dioxide

A bent, pungent gas released by burning sulfur-containing fuels and by volcanic activity, which dissolves readily in water to form an acidic solution.

Used for: Wine and food preservative, bleaching agent, sulfuric acid production

Sulfuric acid

A dense, strong diprotic acid and one of the most heavily produced industrial chemicals in the world, notable for its powerful dehydrating ability.

Used for: Car batteries, fertilizer manufacturing, industrial chemical processing

Tantalum pentoxide

A chemically stable white oxide with a high dielectric constant, formed as a thin insulating layer on tantalum metal that gives tantalum capacitors their reliability.

Used for: Dielectric layer in tantalum electrolytic capacitors for electronics

Technetium dioxide

A dark, insoluble oxide of technetium formed when pertechnetate is reduced, relevant to how technetium behaves in nuclear waste and reactor environments.

Used for: Studied in nuclear waste chemistry for technetium's environmental behavior

Technetium heptoxide

A yellow, volatile solid that is the highest oxide of technetium, formed by burning the metal in oxygen, and dissolves in water to give pertechnetic acid.

Used for: Laboratory intermediate for preparing other technetium compounds

Terbium oxide

A dark brown, mixed-valence oxide containing both Tb3+ and Tb4+ ions, making it the most thermodynamically stable oxide of terbium under normal conditions.

Used for: Precursor for terbium-activated green phosphors used in lighting and displays

Thallium(I) oxide

A black, water-reactive solid that readily absorbs moisture from air to form thallium hydroxide, reflecting how thallium's +1 state behaves more like an alkali metal oxide than a typical post-transition-metal oxide.

Used for: Precursor in the manufacture of specialty optical glass

Thallium(I) sulfate

A colorless, odorless, water-soluble salt whose lack of taste or smell made it dangerously easy to misuse before its restriction, since thallium(I) mimics potassium closely enough to be absorbed by the body.

Used for: Formerly a widely used rodenticide and ant killer, now banned in most countries

Thallium(III) oxide

A black, brittle solid in which thallium sits in its less stable +3 state, making the compound a mild oxidizer that can decompose to thallium(I) oxide on heating.

Used for: Transparent conducting films and component of some thallium-based superconducting ceramics

Thorium dioxide

Known as thoria, a white refractory solid with the highest melting point of any known oxide, which once made it prized for emitting a bright white glow when heated in gas lamp mantles.

Used for: Historic incandescent gas-lantern mantles and high-temperature ceramics

Thorium nitrate

A water-soluble crystalline salt once produced on an industrial scale because fabric soaked in its solution, then ignited, left behind a fragile mesh of thorium dioxide that glowed brilliantly in gas lamps.

Used for: Historic impregnating agent for gas-lantern mantles

Thulium(III) oxide

A pale green rare-earth oxide and the standard commercial form of thulium, one of the least abundant naturally occurring lanthanides.

Used for: Starting material for thulium-doped solid-state and fiber lasers

Tin(IV) oxide

A hard, chemically stable oxide that occurs naturally as the mineral cassiterite, the principal ore from which tin metal is extracted.

Used for: Ore of tin metal and abrasive/polishing compound

Titanium dioxide

A brilliant white, chemically stable oxide that occurs naturally as the minerals rutile and anatase.

Used for: White pigment in paint, sunscreen, food coloring, plastics

Triruthenium dodecacarbonyl

An orange cluster compound built from three ruthenium atoms bridged by carbon monoxide ligands, widely studied as a catalyst and a building block for other ruthenium clusters.

Used for: Catalyst precursor in organic synthesis and organometallic research

Triuranium octoxide

A dark green-black mixed-valence oxide containing uranium in both the +5 and +6 states, and the thermodynamically most stable uranium oxide in air across a wide temperature range. It's the form uranium ore concentrate settles into after milling.

Used for: Standard storage and shipping form of milled uranium ore ("yellowcake")

Tungsten trioxide

A yellow, chemically stable oxide that turns deep blue when it gains electrons, a property exploited in glass that darkens electronically on demand.

Used for: Active layer in electrochromic 'smart' windows and gas sensors

Uranium dioxide

A black, ceramic solid with a fluorite crystal structure in which each uranium atom sits surrounded by eight oxygen atoms. It's the most thermally and chemically stable uranium oxide, holding its solid form up to temperatures near 2865°C.

Used for: Fuel pellets in nuclear power reactors

Vanadium(IV) oxide

A dark blue-black solid notable for its sharp metal-insulator transition near 68°C, at which point its electrical and optical properties change abruptly as the vanadium shifts between electronic states.

Used for: Research material for thermochromic smart-window coatings and switching devices

Vanadium(V) oxide

An orange-yellow solid and the most important commercial vanadium compound, formed from vanadium's most stable +5 oxidation state. It readily gives up and accepts oxygen, which makes it a versatile industrial catalyst.

Used for: Catalyst in sulfuric acid production (contact process) and in vanadium redox flow batteries

Water

A bent covalent molecule held together by polar O–H bonds, whose extensive hydrogen bonding gives it an unusually high boiling point and makes it the near-universal solvent for life and chemistry.

Used for: Universal solvent, drinking water, biological and industrial processes

Xenon trioxide

A colorless, extremely explosive solid formed when xenon fluorides hydrolyze in water, a rare example of xenon bonded only to oxygen.

Used for: Laboratory curiosity illustrating xenon's higher oxidation states

Ytterbium(III) oxide

A white rare-earth oxide and the standard commercial source of ytterbium, stable in air despite ytterbium's occasional access to a +2 oxidation state.

Used for: Precursor for ytterbium-doped fiber laser and amplifier glass

Yttrium aluminum garnet (YAG)

A synthetic garnet crystal that, when doped with neodymium or other rare-earth ions, forms the gain medium of one of the most widely used solid-state lasers.

Used for: Host crystal for Nd:YAG lasers; also cut as a diamond-simulant gemstone

Yttrium barium copper oxide (YBCO)

A ceramic compound famous as the first material found to superconduct above the boiling point of liquid nitrogen, opening the door to more practical high-temperature superconductor research.

Used for: High-temperature superconductor in research and superconducting wires/tapes

Yttrium oxide

A white, high-melting refractory powder and the main commercial form in which yttrium is sold, historically used as a host for red phosphors in CRT televisions.

Used for: Red phosphor host in older displays; precursor for YAG laser crystals and ceramics

Zinc oxide

A fine white powder that is chemically stable and reflects UV light effectively, making it one of the most widely used zinc compounds in both consumer and industrial products.

Used for: Sunscreen and skin-protectant ointments; rubber manufacturing

Zinc sulfate

A colorless, highly soluble crystalline salt that supplies zinc ions for a range of agricultural and health applications, since zinc is an essential trace element for both plants and animals.

Used for: Dietary supplement and agricultural micronutrient fertilizer

Zirconium dioxide (zirconia)

A hard, chemically inert white oxide that, when stabilized with yttria, becomes extremely tough and is cut as a diamond-simulant gemstone (cubic zirconia).

Used for: Cubic zirconia gemstones, dental crowns, and thermal barrier coatings

Zirconium silicate (zircon)

A hard, durable mineral that is the main natural ore of zirconium and one of the oldest minerals found on Earth, prized for its brilliance when cut as a gemstone.

Used for: Gemstone, ceramic glaze opacifier, and primary ore of zirconium