Introduction Hydrogen is the most abundant element in the universe. It is the element with lowest atomic mass. It is a simple element which has only one proton and one electron and no neutrons. It is everywhere in the universe. It is a colorless and odorless gas at room temperature. About 75% of the universe is composed of hydrogen. The stars we see in the sky are nothing but dumps of hydrogen gas only. These produce enormous amounts of energy through the fusion of hydrogen atoms. In smaller stars, hydrogen atoms will colloid and fuse to form helium and other light elements like nitrogen and carbon (essential for life). In the larger stars, fusion products are the lighter and heavier elements like calcium, oxygen, and silicon.
The hydrogen on Earth is mostly found in the form of water only. Hydrogen as an element is only about 0.5 ppm only. This is boon of God to us otherwise hydrogen is very highly flammable and we might have seen hydrogen burning in the atmosphere.
Hydrogen gas forms explosive mixtures with air in concentration between 4 to 74%. and with chlorine in between 5-95%. The reaction can be triggered by a electric spark, heat or sunlight.
Elemental classification - Non MetalThe Name hydrogen has come from Greek origin which means water producer. It is first identified in the year 1766 by Mr. Cavendish, a well-known scientist.
Properties Even though hydrogen is very abundant on earth, very little is found in its elemental form. The reason for this is its low density and very high reactivity. Majority of hydrogen is in water and hydrocarbons.
It is a non-metal. It has the configuration of ns1. This configuration is similar to that of alkali metals. But it has many differences from alkali metals. Hydrogen is placed above these metals in Periodic Table.
Sometimes the hydrogen is placed above halogens in periodic table. But it is very different from halogens also. The ionisation energy is higher than alkali metals. The electron affinity of hydrogen is lesser than that of halogens. Hydrogen reactions are very slow at room temperature due to the strength of H-H bond. It will get activated on heating and reacts with many substances.
Manufacturing Methods Hydrogen is mainly produced in Industry using two methods.
Isotopes of Hydrogen There are three isotopes: