Hydrogen
A colorless, odorless gas; the least dense gas of the known elements. Officially discovered in 1766 by Henry Cavendish, hyrdrogen is the most abundant element in the universe (composing some 90 percent of the molecules). It is the main fuel source of the stars.
Because of its extreme flammability and burning temperature, hydrogen is used in welding, quartz melting and high temperature research. When paired with oxygen, hydrogen forms water.
Hydrogen fuel cells might one day power cars, although many hurdles exist to bringing the technology to market, including making it practical and affordable. A hydrogen fuel cell car would work like this: Hydrogen fuel and oxygen from the air would combine in the fuel cell to produce electricity. The electricity would run an electric motor, which would propel the car. The car would emit only water and heat as its “exhaust.”
Sources:
-- “Fuel Cell Vehicles,” FuelEconomy.gov. http://www.fueleconomy.gov/feg/fuelcell.shtml
-- “How Fuel Cells Work,” How Stuff Works Web site. Accessed Sept. 5, 2007. http://www.howstuffworks.com/fuel-cell.htm
-- “Hydrogen,” Columbia Encyclopedia. Accessed Sept. 5, 2007. http://www.bartleby.com/65/hy/hydrogen.html
