Answers

2014-08-04T17:23:16+08:00
Hydrogen - H, Helium - He, and Nitrogen - N
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2014-08-04T20:23:55+08:00
Hydrogen - H (but usually others write it as H₂ because it is a diatomic molecule)
Helium - He
Nitrogen - N (like hydrogen, it is sometimes written as N₂)
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