Step-by-step explanation:
Ionization reactions are reactions that involve an electrically neutral atom or molecule be converted into electrically charged atom or molecule (ions).
Ions are recognized by the (⁺) and (⁻) signs.
First Reaction: Ions are formed so this option is correct.
Second Reaction: Ions are formed so this option is correct.
Third Reaction: This option is wrong. No ions are formed.
Fourth Reaction: Ions are formed so this option is correct.
Fifth Reaction: Ions are formed so this option is correct.