Question

What is hydrogen? What are different types of hydrogen?

Answer 1

Hydrogen is the first element in the periodic table and has the atomic number one. Those elements which have the same atomic number but different mass number are called isotopes. There are three isotopes of hydrogen namely, protium 1H1, deuterium 1H2 or D and lastly tritium 1H3 or T. The isotopes are different because of the different number of neutrons present in them. In protium, there is no presence of neutrons, whereas in deuterium we have one neutron and in tritium, we have two neutrons. The most prominent form of hydrogen is protium, 0.0156% of hydrogen is present on the earth’s surface as deuterium. For tritium, the concentration is one atom per 1018 atoms of protium. Out of these three isotopes of hydrogen, only tritium is radioactive in nature which emits low energy particles. As the electronic configuration of isotopes is same, they all have similar chemical properties. But they have a difference in their rates of reaction, this happens because of the different bond disassociation enthalpies. They have different physical properties because of the large variations in mass.
The occurrence of hydrogen on earth is difficult due to its light nature. In combined form, 15.4% hydrogen occurs in the earth’s crust and oceans. Hydrogen also occurs in plant and animal tissues, hydrocarbons, proteins, hydrides and many other compounds. In universe, hydrogen is the most abundant element (70% of the total mass) and it is also the principal element of the solar atmosphere. Even the huge planets such as Jupiter and Saturn mainly consist of hydrogen.
Moving on to the properties of hydrogen, it is the lightest known element. It occurs as a diatomic molecule in nature. In spite of being a stable element, it forms many bonds and is a constituent element in a number of compounds. The average atomic weight of hydrogen is 1.0079 amu. Hydrogen is available in many forms, for example, gaseous hydrogen, liquid hydrogen, slush hydrogen and solid hydrogen.