Linked from

The 28 pages that link to Helium, each with the reason it gives.

• MetallicityRelated: Astronomers exclude helium when defining metals, even though it is heavier than hydrogen.

• Gas giantRelated: It is the second major ingredient of gas giant interiors.

• Atmosphere of JupiterRelated: Its abundance helps constrain Jupiter’s atmospheric composition and interior evolution.

• Carbon-dioxide laserRelated: It helps remove heat and depopulate lower laser levels in many carbon-dioxide mixtures.

• Giant planetRelated: Helium contributes to the bulk composition and energy evolution of gas giants.

• Atmosphere of UranusRelated: Helium is the second major gas in Uranus’s atmospheric mixture.

• Disodium helideRelated: Helium’s inertness makes its predicted participation in Na₂He especially striking.

• Toy balloonRelated: Its low density makes it useful for lifting balloons above the surrounding air.