Isotopes of Hydrogen

Hydrogen-1 (¹H), also called protium, the simplest and most common form of hydrogen:

Hydrogen-1 (Protium)

Property	Description
Name	Hydrogen-1 (Protium)
Symbol	¹H or simply H
Atomic Number (Z)	1
Mass Number (A)	1
Isotopic Composition	1 proton, 0 neutrons, 1 electron
Approximate Atomic Mass	1.007825 u
Natural Abundance	~99.985% of all hydrogen on Earth
Oxidation States	+1 (most common), −1 (in hydrides)
Group / Period	Group 1 (alkali metals) / Period 1
Block	s-block
Element Category	Nonmetal

2. Atomic and Subatomic Structure

Proton:
Charge: +1 (1.602 × 10⁻¹⁹ C)
Mass: 1.007276 u
Electron:
Charge: −1 (−1.602 × 10⁻¹⁹ C)
Mass: 0.0005486 u
Neutrons:
None in protium (this is what distinguishes ¹H from deuterium or tritium).
Therefore, ¹H atom = 1 proton + 1 electron.

Name	Symbol	Composition (protons / neutrons / electrons)	Approx. Atomic Mass (u or amu)	Notes
Protium (normal hydrogen)	H or ¹H 1 / 0 n / 1 e⁻	1.007825 u	Most abundant form (~99.985%)
Deuterium D or ²H	1 p / 1 n / 1 e⁻	2.014102 u	Heavy hydrogen isotope
Tritium T or ³H	1 p / 2 n / 1 e⁻	3.016049 u	Radioactive (half-life ≈ 12.32 years)

Ion Masses (approximate) When hydrogen (or its isotopes) lose or gain electrons, their mass changes slightly because an electron’s mass is small (~0.0005486 u).

Ion	Composition	Approx. Mass (u)	Comment
H⁺ (proton)	1 p / 0 n	1.007276 u	Essentially just a proton
D⁺ (deuteron)	1 p / 1 n	2.013553 u	Nucleus of deuterium
T⁺ (triton)	1 p / 2 n	3.015501 u	Nucleus of tritium
H⁻ (hydride ion)	1 p / 0 n / 2 e⁻	1.008 amu (approx.)	Extra electron adds tiny mass

Do other Hydrogen Isotopes exist? Yes