John Cornett, age 13, of Biloxi, !hiss., for his question:
ARE THERE MANY ELEMENTS?
An element is a substance that is made up of only one kind of atom. We know that there are more than 100 elements.
Sometimes elements are found free, or nncombined, in nature. Oxygen in the air is an example of a free element, although oxygen can be mixed with nitrogen (which is also a free element) as well as with other gases.
Most of the time an element will be found in compounds with other elements. An example is found in water, a compound that is made up of the element oxygen combined chemically with the element hydrogen.
Carbon dioxide is a gas compound that is made up of the element oxygen combined chemically with the element carbon.
You can't just mix two elements together and necessarily expect to come up with a compound. You can't put oxygen and hydrogen together in a container at room temperature and expect to come up with water.
However, if a mixture of these two gases is heated, an explosion will occur and water will be formed. With the explosion comes a rapid chemical combination of the two elements in which two atoms of hydrogen and one atom of oxygen combine to form one molecule of water.
Through the years the list of natural elements grew to be about 90. But in recent years new elements have been made by using nuclear reactors and cyclotrons.
Oxygen was discovered in 1772 and hydrogen in 1766. Some of the elements that were known back in the days before the common era include carbon, iron, lead, mercury, gold, silver, tin, sulfur and zinc.
Because it is necessary to save time and space, all elements are given a type of chemical shorthand with symbols. Some have a single letter, such as H for hydrogen; 0 for oxygen; S for sulfur; and B for boron.
But many elements have a symbol that is a capital letter followed by one other letter in the name: He for helium; Zn for zinc; and Ra for radium.
Sometimes the element symbol comes from the Latin name: The Latin name for silver is argentum, and the element symbol is Ag; lead is plumbum and the chemical symbol is Pb.
There is never more than one capital letter in an element's symbol. The language of the symbols was developed by a Swedish chemist named Jons Jakob Berzelius in 1811 and it is now used in all parts of the world.
The symbol for cobalt is written Co, not CO. CO means one molecule of carbon (C) and one molecule of oxygen (O).
Certain kinds of X rays can show what elements are is a substance. If a substance can be broken up or separated into two or more different substances that ware unlike the original substance, it is a compound. If there can be no further breaking up of a substance, it is judged to be an element.