What is a pure gas?

Yes, gas is a pure substance.

Helium gas is a pure substance

Argon is a pure gas, and an element.

Pure Oil Gas Station was created in 1933.

Homogenous (gas is always homogenous, as pure liquid is, when pressurised from pure gas)

nitrogen gas is BASICALLY JUST PLAIN NITROGEN AND THUS IT IS A PURE SUBSTANCE.

Helium is a pure substance

Neon is an element, and as such, is a pure substance.

Pure Hydrochloric Acid is a gas.

Helium is a pure chemical element.

No, hydrogen gas is a pure substance.

Yes, Argon (Ar) is an mono-atomic elementary gas, so it's PURE

No. Natural gas is methane gas (CH4), a pure substance.

Gas is a PURE substance not a mixture in order for it to be considered a mixture it would have to have more than one item making the gas a mixture

Helium is pure as it is on the periodic table.

It is a pure substance. It is a basic gas

Pure argon gas is a homogeneous substance.

Helium gas is homogenous.

none - it's a pure gas, just oxygen none - it's a pure gas, just oxygen

No. Argon gas is a pure substance. It is a noble gas element

Oxygen is an element indicating that is a pure substance.

Pure. (Its nitrous oxide.)

Colourless gas, when pure

Steam. Pure steam is a transparent gas.

No. Krypton gas is an element and therefore a pure substance.