Mike Carmichael, age 14, of El Paso, Texas, for his question:
HOW WAS NATURAL GAS FORMED?
Natural gas was formed billions of years ago when water covered much more of the earth's surface than it does today. The gas started as tiny marine plants and animals.
Down through the ages, great quantities of animals and water plants called plankton died and settled to the ocean floors. There, fine sand and mud drifted down over the plankton. Layer upon layer of these deposits piled up. Their great weight; plus bacteria, heat and other natural forces, changed the chemical compounds in the plankton into natural gas and oil.
The gas and oil flowed into the holes in limestone, sandstone and other porous rocks and sealed the gas and oil beneath.
Later, movements in the earth's crust caused the ancient seas to draw back and dry land appeared over many gas and oil deposits.
Pure natural gas is made up of chemical compounds of the elements hydrogen and carbon. These compounds are called hydrocarbons. Some hydrocarbons are naturally gaseous, some are liquid and some are solid. A hydrocarbon's form depends on the number and arrangement of the hydrogen and carbon atoms in the hydrocarbon molecule.
Natural gas is composed chiefly of methane, the lightest hydrocarbon. In a methane molecule, one atom of carbon is bound together with four atoms of hydrogen.
Other gaseous hydrocarbons usually in natural gas include ethane, propane and butane.
When natural gas burns, the hydrocarbon molecules break up into atoms of carbon and hydrogen. The atoms combine with the oxygen in the air and form new substances. The carbon and oxygen form carbon dioxide, an odorless, colorless gas.
As the molecules break up and recombine, heat is released. Heat is measured in B.T.U.s, or British thermal units, in the customary system of measurement, or in calories in the metric system. One cubic food of burning gas releases about 1,000 B.T.U.s.or 252,000 calories.
The ancient Chinese were the first people known to use natural gas for industrial purposes. Thousands of years ago, they discovered natural gas deposits and learned to pipe the fuel through bamboo poles. They burned the gas to boil away salty water and collect the salt that remained.
During the seventh century A.D., temples with "eternal" fires were built near what is now Baku, Russia. Worshippers came from as far away as Persia and India to see the mysterious, continuous fires, and they wondered at the power of the temple priests. Secret pipes carried natural gas into the shrines from nearby rock fractures.
In 1609, a Belgian chemist and physician named Jan Baptista van Helmont, discovered manufactured gas. He found that a "spirit," which he named gas, escaped from heated coal.
A British engineer named William Murdock lighted his home with gas made from coal in 1792 and he lighted the outside of a factory with gaslight in 1802.
By 1804, Murdock had installed 900 gaslights in cotton mills. He became known as the father of the gas industry.