# How are ions formed? [closed]

I know that $\ce{H2O}$ is neutral. So how does adding one more hydrogen atom to it make it positive ion ($\ce{H3O+}$)?

• Hi Hark, welcome to Chem.SE! Where did you read that addition of an hydrogen atom forms a hydronium ion? In fact, it doesn't. Hydronium ions are formed by addition of a proton to a water molecule. – Gaurang Tandon Feb 24 '18 at 11:51
• So all ions are formed this way? – Hark Feb 24 '18 at 11:53
• Ions are always charged. You cannot hope to form them by combining one atom with another atom. – Gaurang Tandon Feb 24 '18 at 11:54
• Deprotonation of sulphuric acid. Twice. – Gaurang Tandon Feb 24 '18 at 11:58
• A "neutral ion" does not exist. Neutral gases of a similar formula - SO3 and SO2 - do exist, though they are not ions. – Gaurang Tandon Feb 24 '18 at 12:01

The flaw in the question is exactly what Gaurang Tandon said: $\ce{H3O^+}$ is formed by a water molecule and a proton ($\ce{H^+}$), not a hydrogen atom.
$$\ce{H2O + H^+ -> H3O^+}$$
$$\ce{H2O + H^. -> H3O^+}$$