Symbol: H
Atomic Number: 1
Atomic Weight: 1.00794
Electron Configuration: 1s1
Classification: Non-metal
Number of Protons/Electrons: 1
Isotops: Protium H-1 (stable), Deuterium H-2 (stable), Tritium H-3 (half-life 12.3 years)
Crystal Structure: Hexagonal
Name Origin: from Greek: hydro (water) + genes (former, producer)
Hydrogen (H) is the simplest and the lightest element. Its atom has one proton and one electron.
Nitrogen was discovered in 1766 by Henry Cavendish.
It is an important constituent of organic compounds of the living organisms. DNA molecules forming the genetic code contain hydrogen. Hydrogen and oxygen form water (H2O). Hydrogen is the most abundant element of the visible universe: it makes up about 90% of the universe mass.
Molecules of gaseous hydrogen are normally diatomic H2.
Gaseous hydrogen is a colorless, odorless, tasteless gas. It is chemically active gas forming numerous compounds with other elements. Hydrogen is extremely flammable.
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Most of hydrogen in the world is produced by stream reforming, which is the least expensive method of the isolation of hydrogen.
In this method steam heated to 2010°F (1099°C) reacts with methane (CH4):
H2O + CH4 = CO + 3H2
Another version of steam reforming process uses reaction of coke (instead of methane) with steam:
H2O + C = CO + H2
Carbon monoxide (CO) reacts then with hot steam in presence of iron oxide:
CO + H2O = CO2 + H2
Acidified water is decomposed in an electrolytic cell. Hydrogen is evolved at the negative electrode and oxygen is evolved at the positive electrode:
2H2O = 2H2 + O2
This method is used for laboratory preparation of hydrogen:
Fe + H2SO4 = FeSO4 + H2
This method is also used for laboratory preparation of hydrogen:
CaH2 + 2H2O = Ca(OH)2 + 2H2
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Ammonia is produced by the reaction between nitrogen and Hydrogen (Haber process). Ammonia is then used for fabrication of fertilizers, nitric acid (Ostwald process), nitro-glycerine (explosive).