Hydrogen
Atomic Number: 1
Atomic Weight: 1.00794
Melting Point: 13.81 K (-259.34°C or -434.81°F)
Boiling Point: 20.28 K (-252.87°C or -423.17°F)
Density: 0.00008988 grams per cubic centimeter
Phase at Room Temperature: Gas
Element Classification: Non-metal
Period Number: 1
Group Number: 1
History
Scientists had been producing hydrogen for years before it was recognized as an element. Written records indicate that Robert Boyle produced hydrogen gas as early as 1671 while experimenting with iron and acids. Hydrogen was first recognized as a distinct element by Henry Cavendish in 1766.
Brief description
Hydrogen is the lightest element. It is by far the most abundant element in the universe and makes up about about 90% of the universe by weight. Hydrogen as water (H2O) is absolutely essential to life and it is present in all organic compounds. Hydrogen is the lightest gas. Hydrogen gas was used in lighter-than-air balloons for transport but is far too dangerous because of the fire risk (Hindenburg). It burns in air to form only water as waste product and if hydrogen could be made on sufficient scale from other than fossil fuels then there might be a possibility of a hydrogen economy.
About 10 percent of the weight of living organisms is hydrogen - mainly in water, proteins and fats. Liquid hydrogen has the lowest density of any liquid. Solid, crystalline hydrogen has the lowest density of any crystalline solid. Hydrogen is believed to be one of three elements produced in the Big Bang; the others are helium and lithium. We owe most of the energy on our planet to hydrogen. The Sun's nuclear fires convert hydrogen to helium releasing a large amount of energy in the process. Hydrogen forms both positive and negative ions. It does this more readily than any other element. Hydrogen is the most abundant element in the universe. Hydrogen reacts explosively with the elements oxygen, chlorine and fluorine