What combination of these atoms or ions have complete valence shells? He, I^-, Pb²⁺, Mg²⁺, H^-,Tl⁺

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Atoms or ions with complete valence shells have a stable electron configuration, typically achieving a noble gas configuration. Helium (He) naturally has a complete valence shell with 2 electrons. The ions listed as I^- (I^-), Mg²⁺ (Mg^2+), and H^- (H^-) have configurations indicating they have gained or lost electrons to fill or empty their valence shell, achieving stability.

What Combination of These Atoms or Ions Have Complete Valence