Hydrogen has three isotopes of which tritium is the most common
Hydrogen never acts as cation in ionic salts
Hydronium ion,H3O+exists freely in solution
Dihydrogen does not act as a reducing agent
Hydrogen has three isotopes of which protium(¹H)is the most common. The percent abundance of protium, deuterium and tritium are 99.985, 0.0156 and 10⁻⁵⁵ respectively.