KnowraHeliumLinked fromLinked fromThe 28 pages that link to Helium, each with the reason it gives.All 28Broader topic 8Related 8Narrower topic 4Compared with 8Ionization 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.Fraunhofer linesBroader topic: A yellow solar spectral line revealed helium in 1868.William RamsayBroader topic: Ramsay isolated terrestrial helium from the mineral cleveite in 1895.Chemical inertnessBroader topic: Its inertness supports uses such as leak detection and protective atmospheres.Norman LockyerBroader topic: Lockyer named this element after recognizing its spectral signature in sunlight.Period 1 elementBroader topic: Helium completes Period 1 with the first filled electron shell.Trouton's ruleBroader topic: Its unusual quantum behavior and weak interactions make simple liquid rules unreliable.