Linked from

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

• HydrogenCompared with: The next element shows how adding one proton changes nuclear stability and chemical behavior.

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

• Ionization energyBroader topic: Its compact, filled shell gives it an exceptionally high first ionization energy.

• Noble gasBroader topic: Its first shell is full with two electrons, not the octet typical of heavier noble gases.

• AirshipCompared with: Its safety advantage over hydrogen addressed one central airship fire risk, while scarcity and cost limited use.

• Fraunhofer linesBroader topic: A yellow solar spectral line revealed helium in 1868.

• Helium-4Narrower topic: Helium-4 is the element’s overwhelmingly common isotope.

• William RamsayBroader topic: Ramsay isolated terrestrial helium from the mineral cleveite in 1895.

• Noble gas compoundCompared with: Its very high ionization energy and small size make ordinary chemical bonding exceptionally difficult.

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

• ArgonCompared with: Helium is lighter and rarer in Earth’s atmosphere, though both gases are chemically unreactive.

• Chemical inertnessBroader topic: Its inertness supports uses such as leak detection and protective atmospheres.

• Liquid heliumNarrower topic: Liquid helium is the low-temperature liquid phase of this element.

• Periodic table blocksCompared with: Its configuration places it in the s block by filling, although it is displayed with noble gases.

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

• NeonCompared with: Helium is lighter and far more volatile, while neon produces a stronger visible glow.

• Norman LockyerBroader topic: Lockyer named this element after recognizing its spectral signature in sunlight.

• Gas balloonCompared with: Helium reduces fire risk, though its scarcity and cost can limit balloon use.

• Helium compoundsNarrower topic: Its exceptionally stable electron shell makes ordinary chemical bonding difficult.

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

• Hindenburg disasterCompared with: The Hindenburg used flammable hydrogen; helium offered a safer but less available alternative.

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

• Helium atomNarrower topic: The atom is the individual particle of the element helium.

• 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.

• Period 1 elementBroader topic: Helium completes Period 1 with the first filled electron shell.

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

• Trouton's ruleBroader topic: Its unusual quantum behavior and weak interactions make simple liquid rules unreliable.