Scientists use a kind of shorthand to write about atoms and elements. Each element has its own symbol. Some of the symbols are easy, because they are the first letter of the name of the element. For carbon, they use the letter C; for oxygen they use the letter O.

What letters might be used for iodine (I), uranium (U), and hydrogen (H)?

The difficulty begins when we realize that some atomic elements have names beginning with the same letter as other elements' names. For example, hydrogen and helium both begin with the letter "H". If we use "H" as the symbol for hydrogen, what can we use for "helium?" The scientists, being smart folks, determined that some elements could have more than one letter in their symbols. The symbol for helium is "He." Since "C" is the symbol for carbon, and they needed a symbol for calcium, they used "Ca." The symbol for sulfur is "S"; the symbol for silicon is "Si." That works pretty well, doesn't it?

Don't go to sleep yet; it gets harder. There are eleven symbols that don't make the same kind of sense to us as those above.

As we have done in many areas of study, we have adopted some symbols for elements from those used by the Greeks and Romans. Early in their civilizations, they used (to name a few) gold, silver, and iron. The Greeks spoke Greek and the Romans spoke Latin; their words and symbols fit into their languages. The symbol for gold is "Au", which are the first letters in "aurum." The symbol for silver is "Ag" (argentum), the symbol for iron is "Fe" (ferrum).

The symbols are easy to memorize, and there are clues for each one. It seems like a secret language that not everybody knows!