Which Elements Are Gases at Room Temperature? All 11, Explained

At standard room conditions (25 °C and 1 atmosphere), 11 elements are gases. They fall neatly into two groups: five that exist as pairs of atoms, and six noble gases that exist as single atoms.

The 11 gaseous elements

Element	Symbol	Form	Boiling point
Hydrogen	H	H₂	−252.9 °C
Nitrogen	N	N₂	−195.8 °C
Oxygen	O	O₂	−183.0 °C
Fluorine	F	F₂	−188.1 °C
Chlorine	Cl	Cl₂	−34.0 °C
Helium	He	He	−268.9 °C
Neon	Ne	Ne	−246.1 °C
Argon	Ar	Ar	−185.9 °C
Krypton	Kr	Kr	−153.2 °C
Xenon	Xe	Xe	−108.1 °C
Radon	Rn	Rn	−61.7 °C

(Oganesson, element 118, sits under radon but is predicted to be a solid, and too few atoms have ever existed to know for sure.)

Where they are on the table

Look at the periodic table and the gases are all on the right-hand side — except hydrogen, which is at the top left. That’s no coincidence: gases are made of nonmetals, and the nonmetals are concentrated in the upper right.

Why they’re gases

An element is a gas at room temperature when the forces between its particles are too weak to hold them together as a liquid at 25 °C.

• The noble gases exist as single atoms with completely full electron shells. They don’t bond to each other at all, and only weak London dispersion forces attract one atom to the next. Those forces grow with atom size, which is why boiling points climb steadily from helium (−269 °C) to radon (−62 °C).
• The diatomic gases — H₂, N₂, O₂, F₂, Cl₂ — have strong covalent bonds within each molecule, but the molecules are small and nonpolar, so the attractions between molecules are weak.

Chlorine has the highest boiling point of the diatomic gases (−34 °C) because Cl₂ is the largest of them. The next halogen down, bromine (Br₂), is big enough to be a liquid, and iodine (I₂) is a solid. See the halogens and diatomic elements.

What they’re used for

• Nitrogen makes up about 78% of the air. It’s used to keep packaged food fresh, and as a liquid for freezing.
• Oxygen (about 21% of air) is essential for respiration and combustion; it’s used in hospitals, steelmaking and welding.
• Hydrogen is used to make ammonia for fertilizers, in oil refining, and increasingly as a clean fuel.
• Chlorine disinfects drinking water and swimming pools, and is used to make PVC and countless other chemicals.
• Fluorine is used to make fluoride toothpaste additives, refrigerants, PTFE non-stick coatings and uranium hexafluoride for nuclear fuel enrichment.
• Helium fills balloons and airships and cools MRI magnets.
• Neon glows orange-red in signs.
• Argon (almost 1% of air — much more than carbon dioxide) provides an inert atmosphere for welding and fills incandescent light bulbs.
• Krypton and xenon are used in high-performance lighting; xenon is also a general anaesthetic and an ion-thruster propellant for spacecraft.
• Radon is radioactive and mostly a health concern: it seeps out of rocks into basements and is a leading cause of lung cancer after smoking.

Colours

Most of these gases are colourless. The exceptions are fluorine, pale yellow, and chlorine, yellow-green — the colour that gives chlorine its name (Greek chlōros, “pale green”).

Quick answers

How many elements are gases at room temperature? Eleven.

Is carbon dioxide an element? No. It’s a compound of carbon and oxygen. Only single elements count here.

Which gas element is the heaviest? Radon, about eight times denser than air.