Answer : The correct option is, [tex]H_3O^+[/tex]
Explanation :
The name of the [tex]H_3O^+[/tex] cation is hydronium ion and it is derived from the protonation of the water. Or we can say that the hydronium ion is produced when the Arrhenius acid dissolves in water.
The protonation of water reaction is represented as,
[tex]H_2O+H^+\rightarrow H_3O^+[/tex]
Hence, the formula for the hydronium ion is, [tex]H_3O^+[/tex]
