O -> [Add \ a \ hydrogen \ atom] \underset{Hydroxide}{HO} ->[Add \ another \ hydrogen \ atom] \underset{Water}{H2O}
\underset{Sodium \ chloride}{NaCl} + \underset{Sulfuric \ acid}{H2SO4}-> \underset{Sodium \ hydrogen-sulfate}{NaHSO4} + \underset{Hydrogen \ chloride}{HCl}
^{151}_{63}Eu_{88} ->[a] ^{147}_{61}Pm_{86} ->[b-] ^{147}_{62}Sm_{85} ->[a]^{143}_{60}Nd_{83}
^8_4Be_4 ->[a] 2 ^4_2He_2
\underset{Hydrogen \ gas}{H2} + \underset{Water}{H2O} -> \underset{Hydronium}{H3O+} \ \underset{Hydrogen}{H}