Element Names and Symbols

Dalton used symbols to represent his atoms. However, he did not use the same symbols that we use. He used circles with markings to represent the various individual atoms. He used circles with dots, lines, crosses and shading in them. When he ran out of marks he put letters in the circles to represent the elements. Each different symbol represented a different kind of atom--the atom of a different element.

About ten years later, in Sweden, Berzelius suggested just using letters to represent atoms of each element and also to represent the elements in general. These are the symbols that we use today. Because we use the symbols in two different ways, you need to pay attention to the context in which a symbol for an element is used. Realize that sometimes it just represents the element and sometimes it represents an atom of the element.

Names of Elements

Some elements have been known since ancient times, even though they may not have been known to be elements at that time. They were known prior to and during the time that our various cultures and languages developed. Consequently some of these elements have names that are different in each culture or each language. Gold is a good example. Probably every culture has a name for the element gold, just as every culture would have its own name for the compound water and its own name for the sun. So that we might have just one symbol for each element, Berzelius based the symbol on the Latin name for each element.

In the other parts of this section you will be introduced to:

• symbols used for the elements in a way that will hopefully make them a little easier for you to remember (or at least understand why some of them are so different than the names we use for those elements)

• chemical names for compounds so that you will be able to use them to determine what elements are contained in them.

Symbols For Elements

Some symbols should make sense to you immediately--such as C for carbon, O for oxygen and S for sulfur. This is because the English name is very similar to the Latin name for these elements. Some of the others may be quite baffling--such as Na for sodium, K for potassium, Fe for iron, Au for gold, and Ag for silver. This is because the English and Latin names for these elements are quite different.

Some of the elements have a single letter for a symbol. These are generally the very common ones such as oxygen, or carbon, or they might be the only elements that start with that particular letter. All of the symbols that are a single letter use an upper case letter. (C not c; O not o; etc.)

Most of the elements have double letter symbols, and you have to make sure that you use an upper case for the first letter and a lower case for the second letter. That second letter is usually the first non-common letter between elements that have names starting with the same letter. For example, chromium and chlorine both start with "C" and so does the symbol. They both have "h" for the second letter but the third letter is different - it's "l" for chlorine, "r" for chromium--and thus the symbols for those two elements are Cl for chlorine and Cr for chromium.

Over the years chemists not only named and symbolized the elements, they also discovered new ones and made a great many observations and measurements of the elements. They observed similarities and patterns among the pure elements which cried out for someone to arrange them in some sort of organizational scheme. This was done and the result, after a number of modifications, is the modern periodic table of the elements (below). We will have much more to say about the periodic table and its strange structure later in the course. You will find that it has a lot to do with the ways that elements combine with one another to form compounds.

Chemical Names For Compounds

We will spend more time later in this course working with the intricacies of chemical names. But there are a couple important things you should learn now. One is the reason for having a systematic method for naming chemical compounds. The other is identifying the elements contained in compounds, which is the first step in determining the formula and composition of compounds.

As chemists learned more and more about the composition of simple compounds, it became important to develop a system for naming these compounds in a way that showed their elemental composition. Common and descriptive names like salt, cinnabar, laughing gas, and blue vitriol tell us nothing about what is in a compound. Chemical names like sodium chloride, magnesium oxide, mercuric sulfide, nitrous oxide and cupric sulfate do a better job of conveying information about what elements are contained in a compound.

Here are some simple guidelines of what to look for in chemical names:

• Generally when two elements combine, the name of the compound contains the names of both elements with the ending on the second element changed to "-ide."
  Example: sodium chloride, compound of sodium and chlorine

• Sometimes the name of the first element will also be altered slightly, often ending in "-ic" or "-ous."
  Example: nitrous oxide, compound of nitrogen and oxygen

• Sometimes the alteration will be more significant, often involving the Latin name for an element. You are not required to know these Latin names, but familiarizing yourself with the ones you see may be useful.
  Example: ferric bromide, compound of iron (ferrum in Latin) and bromine

• Sometimes you will see roman numerals in names. These indicate the element's valence, a concept we will learn about in later lessons.
  Example: nickel (II) chloride, compound of nickel and chlorine

• Sometimes names will contain Greek prefixes (mono, di, tri, etc.). These indicate the number of atoms in a given compound, and we will learn more about them in later lessons
  Example: dinitrogen tetroxide, compound of nitrogen and oxygen

• When a compound ends in "-ate" or "-ite," it is a good indication that oxygen is present in the compound in addition to other elements that might be evident
  Example: cupric nitrate, compound of copper, nitrogen, and oxygen