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→Key Stage 3
===Meaning===
[[File:HeliumSymbol.png|right|300px|thumb|The [[Chemical Symbol|chemical symbol]] for [[Helium]].]]
[[Helium]] is a [[Group 0]] [[element]] with an [[Atomic Number|atomic number]] of 2.
===About Helium===
: [[Helium]] has the [[Chemical Formula|chemical formula]] [[Helium|He]].
: [[Helium]] [[gas]] is less [[density|dense]] than [[air]].
: An [[atom]] of [[Helium]] has a full [[Outer Shell|outer shell]] of two [[electron]]s so it is [[inert]].
==Key Stage 4==
===Meaning===