Isotopes of Hydrogen

Isotope :
      Atoms of elements having the same atomic number with different mass numbers are called Isotopes.
      Hydrogen has three naturally occurring isotopes with mass number 1, 2, and 3, each possesing an atomic number of one.

• Protium or Hydrogen. ₁H¹    
• Deuterium or Heavy water. ₁H²
• Tritium. ₁H³

Protium Or Hydrogen

• In chemistry protium is refers to hydrogen -1.
• Protium is the most common isotope of the element hydrogen. 
• Protium has one proton, no neutrons, and one electron revolving around it.
• It constitues 99.98 % of total hydrogen available in nature.
• It is a stable isotope.
• Its mass number is one. 

The Structure of protium is given below.

Deuterium Or Heavy water :

• Deuterium is also known as hydrogen-2 or heavy water. Its symbol is D or ₁H² 
• ^{Deuterium is otherwise called as deuteron.}
• ^{It contain one proton, one neutron and one solitary electron revolving around the nucleus.}
• ^{It is a stable isotopes.}
• ^{The name deuterium comes from the Greek word 'deutero' which means 'second'. It denote two particles composing the nucleus.}
• ^{Its chemical properties are similar to protium but their reaction rates are different.}
• ^{Its mass number is two.}

The structure of Deuterium is given below.

Tritium:

• Tritium is also known as hydrogen-3. Its symbol is T or ₁H³ 
• Its otherwise called as Triton.
• It contain one proton and two neutrons.
• It occurs in the upper atmosphere only were it is continuously formed by nuclear reactions induced by cosmic rays.
• The name Tritium comes from the Greek word 'tritos' meaning "third".
• Its mass number is three.
• Tritium has a half-life of 12.3 years and emits a very weak beta ( ᵝ ) particle.

The structure of Tritium is given below.