Gases: The Complete List

From lab benches to the engines that power cities, gases are all around us and play roles in chemistry, manufacturing, and everyday life. A compact, well-organized list helps you locate key properties quickly without sifting through long reference texts.

There are 45 Gases, ranging from 1,3-Butadiene to Xenon. For each entry you’ll find below the data organized as Formula,Molecular weight (g/mol),Category so you can compare composition, molar mass, and classification at a glance — you’ll find below.

What does the “Category” column tell me?

The “Category” label groups gases by function or hazard (for example: noble, inert, flammable, toxic), giving a quick sense of typical uses and safety concerns; use it as a starting point for handling or storage decisions but consult material safety sheets for detailed guidance.

How reliable are the listed molecular weights and where do they come from?

Molecular weights are standard, widely accepted values (rounded to useful precision) derived from sources like IUPAC and chemical databases; small variations can occur due to isotopic composition, so verify exact numbers from primary references when precision matters.

Gases

Images and Descriptions

Hydrogen

The lightest and most abundant chemical substance, hydrogen is a colorless and highly flammable gas. It is used as a clean fuel source, in ammonia production for fertilizers, and for processing foods and metals.

Helium

The second-lightest element, this inert noble gas is known for making balloons float and voices squeaky. It is used in cryogenics, deep-sea diving gas mixtures, and for creating inert atmospheres for welding and semiconductor growth.

Nitrogen

Making up about 78% of Earth’s atmosphere, nitrogen is a colorless, odorless, and largely inert gas. It is crucial for life and is used to produce fertilizers, as a cryogenic liquid, and to inflate tires.

Oxygen

Essential for respiration in most terrestrial life, this highly reactive gas makes up 21% of our atmosphere. It supports combustion and is used in medicine, steel manufacturing, and as a rocket propellant oxidizer.

Fluorine

The most electronegative and reactive of all elements, fluorine is a pale yellow, highly toxic, and corrosive gas. It is used in the production of uranium hexafluoride for nuclear fuel and in compounds like Teflon.

Neon

Famous for its bright reddish-orange glow in signs, neon is an inert noble gas found in trace amounts in the atmosphere. Besides lighting, it is used in vacuum tubes, high-voltage indicators, and as a cryogenic refrigerant.

Chlorine

A pungent, greenish-yellow gas, chlorine is a powerful oxidizing agent and disinfectant. It is widely used to purify drinking water and swimming pools, and in the production of plastics like PVC and many other chemicals.

Argon

The third-most abundant gas in Earth’s atmosphere, argon is a colorless and inert noble gas. Its unreactivity makes it perfect for use as a shielding gas in welding and in incandescent light bulbs to protect the filament.

Krypton

A rare and unreactive noble gas, krypton is used in some high-performance light bulbs, flash lamps for photography, and in lasers. It is denser than air and produces a whitish light when electrified.

Xenon

An extremely rare, dense, and unreactive noble gas, xenon produces a brilliant white flash when excited by electricity. It is used in high-intensity lamps for film projectors, car headlamps, and as a general anesthetic.

Radon

A radioactive, colorless, and odorless noble gas, radon is formed by the natural decay of uranium in soil and rocks. It can accumulate in buildings and is a significant cause of lung cancer.

Water Vapor

The gaseous state of water, it is one of the most abundant gases in the atmosphere. It is the most significant natural greenhouse gas, playing a crucial role in Earth’s weather and climate systems.

Carbon Dioxide

A colorless gas essential for plant life through photosynthesis, it is a byproduct of respiration and combustion. Used to carbonate beverages and in fire extinguishers, it is also a major man-made greenhouse gas.

Carbon Monoxide

A colorless, odorless, and highly toxic gas produced by the incomplete combustion of carbon-containing fuels. It is a dangerous indoor air pollutant and is used industrially as a reducing agent in metallurgy.

Nitrous Oxide

Commonly known as laughing gas, this sweet-smelling gas is used as a mild anesthetic and as a propellant in aerosol cans. It is also a powerful greenhouse gas, produced by agriculture and industrial processes.

Nitric Oxide

A highly reactive gas that plays a key role as a signaling molecule in biology. In the atmosphere, it is an air pollutant from vehicle exhaust and power plants, contributing to smog and acid rain.

Nitrogen Dioxide

A reddish-brown gas with a sharp, biting odor, nitrogen dioxide is a prominent air pollutant from vehicle emissions. It contributes to the formation of smog and acid rain and can cause significant respiratory problems.

Sulfur Dioxide

A toxic gas with a pungent, irritating smell like a burnt match. It is released by volcanoes and industrial processes, primarily the burning of fossil fuels. It is a primary cause of acid rain.

Ozone

A pale blue gas with a distinctively pungent smell. In the stratosphere, it forms the protective ozone layer, but at ground level, it is a harmful air pollutant and a key component of smog.

Methane

The primary component of natural gas, methane is a potent greenhouse gas and an important fuel. It is produced by natural biological processes, like in wetlands and livestock digestion, and by industrial activities.

Ammonia

A colorless gas with a characteristic pungent smell, ammonia is vital for producing fertilizers, plastics, and explosives. It is also used as a refrigerant and in many household cleaning products. It is toxic and corrosive.

Hydrogen Sulfide

A flammable, colorless gas known for its strong “rotten egg” smell. It occurs naturally from volcanic activity and anaerobic decay. It is highly toxic, corrosive, and a significant safety concern in the oil and gas industry.

Hydrogen Chloride

A corrosive, colorless gas that forms white fumes of hydrochloric acid upon contact with atmospheric humidity. It is used to produce vinyl chloride for PVC, clean metals, and in semiconductor manufacturing.

Hydrogen Cyanide

An extremely poisonous gas with a faint, bitter almond-like odor that not everyone can detect. It is used in chemical synthesis and as a fumigant, but is highly regulated due to its extreme toxicity.

Phosphine

A colorless, flammable, and extremely toxic gas with an unpleasant odor of garlic or decaying fish. It is used as a fumigant for stored grain and in the semiconductor industry as a doping agent.

Silane

The silicon analogue of methane, silane is a colorless gas that ignites spontaneously in air (pyrophoric). It is a fundamental material in the electronics industry for depositing thin layers of pure silicon.

Ethane

The second-largest component of natural gas, ethane is a colorless, odorless gas. It is primarily used as a petrochemical feedstock to produce ethylene, a building block for a wide range of plastics and chemicals.

Propane

A common fuel gas used for home heating, cooking, and in vehicles, often sold as liquefied petroleum gas (LPG). It is a byproduct of natural gas processing and petroleum refining and is heavier than air.

Butane

A flammable hydrocarbon gas commonly used as a fuel in lighters and portable stoves, and as a propellant in aerosol sprays. It is typically found in liquefied petroleum gas (LPG) along with propane.

Ethylene

Also known as ethene, this is the world’s most produced organic compound. It is a crucial building block for plastics like polyethylene and is also a natural plant hormone that ripens fruit.

Propylene

Also known as propene, this is the second most important starting product in the petrochemical industry. It is used to produce polypropylene plastic, a versatile material used in packaging, textiles, and auto parts.

Acetylene

The simplest alkyne, acetylene is a colorless gas widely used as a fuel for welding and cutting due to the high temperature of its flame. It is unstable in its pure form and is usually handled as a solution.

Formaldehyde

A pungent-smelling gas used in the production of resins, building materials, and as a preservative. It is a common indoor air pollutant released from pressed-wood products and is a known human carcinogen.

Vinyl Chloride

A colorless, toxic, and carcinogenic gas primarily used to produce polyvinyl chloride (PVC), a common plastic. Its release into the environment is strictly regulated due to significant health and environmental risks.

Sulfur Hexafluoride

An extremely potent and persistent greenhouse gas, sulfur hexafluoride is non-toxic and inert. It is used as an electrical insulator in high-voltage equipment like circuit breakers and as a gaseous tracer.

Nitrogen Trifluoride

A colorless, non-flammable gas with a slightly musty odor. It is primarily used in the manufacturing of semiconductors and flat-panel displays as an etchant, but is also a very potent greenhouse gas.

Carbon Tetrafluoride

Also known as tetrafluoromethane, this is a non-flammable and stable gas. It is used in electronics manufacturing as a refrigerant and plasma etchant, but is an extremely potent and long-lived greenhouse gas.

Dichlorodifluoromethane

Also known as Freon-12, this was a widely used refrigerant and aerosol propellant. It is a chlorofluorocarbon (CFC) now banned by the Montreal Protocol due to its severe damage to the ozone layer.

Phosgene

A colorless, highly toxic gas with an odor described as newly mown hay. It was notoriously used as a chemical weapon in WWI and is now an important industrial chemical for making plastics and pesticides.

Dimethyl Ether

A colorless gas that is a promising clean-burning alternative to propane in LPG. It is used as an aerosol propellant and is being explored as a diesel fuel substitute due to its high cetane number.

Methyl Mercaptan

An extremely foul-smelling gas reminiscent of rotten cabbage, also known as methanethiol. It is added in trace amounts to otherwise odorless fuel gases like propane and natural gas to make leaks detectable by smell.

1,3-Butadiene

A colorless gas with a mild gasoline-like odor, it is a key industrial chemical used to make synthetic rubber for tires. It is flammable and classified as a carcinogen, posing a health risk from industrial emissions.

Ethylene Oxide

A flammable, colorless gas with a faintly sweet odor. It is a crucial industrial chemical used for making other chemicals like ethylene glycol (antifreeze) and for sterilizing medical equipment and spices. It is carcinogenic.

Acetaldehyde

A flammable, colorless liquid with a pungent, fruity odor that is gaseous at room temperature (boils at 20.2°C). It’s found in coffee and ripe fruit, and is an industrial chemical and air pollutant.

Hydrogen Fluoride

A highly corrosive and toxic gas that boils just below room temperature (19.5°C). It is a crucial industrial chemical used to produce most fluorine-containing compounds, including refrigerants and aluminum.