Hydrogen|Before 17th Century|Resemblance Of H With Alkali Metals|Oxidation State|Differences Of H With Alkali Metals|Resemblance With Halogens|Differences With Halogens|Isotopes Of Hydrogen|Comparison Of The Nucleus|Comparison Of Isotopes Of Hydrogen|Laboratory Preparation Of Dihydrogen|Commercial Production Of Dihydrogen|Physical Properties Of Dihydrogen|Chemical Properties|Uses Of Dihydrogen|Water|Chemical Properties Of Water|OMR

Preparation Of Dihydrogen|Laboratory Preparation Of H2|Questions|Commercial Production Of H2|Physical Properties Of Dihydrogen|Chemical Properties Of Dihydrogen|Uses Of Dihydrogen|Hydrides|OMR

Overview OF Chapter|| Abundance OF Hydrogen||Position OF Hydrogen in Periodic Table|| Isotope OF Hydrogen||Isotope Effect|| Dihydrogen||Preparation Properties & Uses

Hydrogen Peroxide (H2O2)|Method Of Preparation|Strength Of H2O2|Physical Property Of Hydrogen Peroxide|Structure Of H2O2|Chemical Properties Of Hydrogen Peroxide|Storage Of H2O2|Uses Of H2O2|Heavy Water|Hydrogen As A Fuel|Hydrogen Economy|OMR

Can You Answer These Questions?|History Of Hydrogen|Interesting Facts About Hydrogen4|Questions|Occurrence Of Hydrogen|Isotopes Of Hydrogen|Isotope Effect & Use Of Tritium|Position Of Hydrogen In Periodic Table|How Hydrogen Differs From Alkali Metals As Well As Halogens?|OMR

The isotopes of hydrogen have different physical properties due to difference in mass. They have almost same chemical properties with a difference in their rates of reactions which is mainly due to

P Block Elements|Periodic Table|Chemical Properties|Anomalous Behavior Of N|Reaction With Hydrogen|Bond Angle|Reaction With Oxygen|Reaction With Halogen|Reaction With Metals|OMR|Summary

Hydrogen accounts for approximately 75% of the mass of the universe. Hydrogen serves as the nuclear fuel of our Sun and other stars, and these are mainly composed of hydrogen. On the earth, though hydrogen is rarely found in the uncombined state. Since the earth's gravity is too weak to hold such light molecules, nearly all the H_2 originally present in the earth's atmosphere has been lost to space. In the earth's crust and oceans, hydrogen is found in water, petroleum, proteins, carbohydrates and other compounds and it is the ninth most abundant element on a mass basis. Hydrogen has three isotopes : hydrogen or protium () , deuterium or heavy hydrogen (D or ), tritium (T or ) . The physical properties of the three isotopes are different due to the difference in their masses, i.e. isotope effect. The chemical properties of the three isotopes are similar as they have the same electronic configuration. Reaction between hydrogen and oxygen is highly exothermic, and gas mixtures that contain as little as 4% by volume hydrogen in oxygen (or in air) are highly flammable and potentially explosive. 2H_(2(g))+O_(2(g)), DeltaH^(ɵ)=-485 kJmol^(-1) As hydrogen is environmentally clean it is an enormously attractive fuel. 'Hydrogen economy' is an emerging field in which it is thought that our energy needs can be met by gaseous, liquid and solid hydrogen. As hydrogen is no a naturally occuring substance such as coal, oil or natural gas, energy must be exploaded to produce hydrogen before it can be used. If an isotope of hydrogen has one neautron in its atom, its atomic number and atomic mass will respectively be