Introductory Chemistry: A Foundation - Zumdahl S.S., DeCoste D.J. 2019

Chemical Foundations: Elements, Atoms, and Ions
Symbols for the Elements

Objective

· To learn the symbols of some elements.

The names of the chemical elements have come from many sources. Often an element’s name is derived from a Greek, Latin, or German word that describes some property of the element. For example, gold was originally called aurum, a Latin word meaning “shining dawn,” and lead was known as plumbum, which means “heavy.” The names for chlorine and iodine come from Greek words describing their colors, and the name for bromine comes from a Greek word meaning “stench.” In addition, it is very common for an element to be named for the place where it was discovered. You can guess where the elements francium, germanium, californium,* and americium* were first found. Some of the heaviest elements are named after famous scientists—for example, einsteinium* and nobelium.*

We often use abbreviations to simplify the written word. For example, it is much easier to put MA on an envelope than to write out Massachusetts, and we often write USA instead of United States of America. Likewise, chemists have invented a set of abbreviations or element symbols for the chemical elements. These symbols usually consist of the first letter or the first two letters of the element names. The first letter is always capitalized, and the second is not. Examples include

Sometimes, however, the two letters used are not the first two letters in the name. For example,

The symbols for some other elements are based on the original Latin or Greek name.

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Various forms of the element gold.

A list of the most common elements and their symbols is given in Table 4.3. You can also see the elements represented on a table in Fig. 4.9. We will explain the form of this table (which is called the periodic table) in later chapters.

Table 4.3. The Names and Symbols of the Most Common Elements

Chemistry in Focus Trace Elements: Small but Crucial

We all know that certain chemical elements, such as calcium, carbon, nitrogen, phosphorus, and iron, are essential for humans to live. However, many other elements that are present in tiny amounts in the human body are also essential to life. Examples are chromium, cobalt, iodine, manganese, and copper. Chromium assists in the metabolism of sugars, cobalt is present in vitamin , iodine is necessary for the proper functioning of the thyroid gland, manganese appears to play a role in maintaining the proper calcium levels in bones, and copper is involved in the production of red blood cells.

It is becoming clear that certain trace elements are very important in determining human behavior. For example, lithium (administered as lithium carbonate) has been a miracle drug for some people afflicted with bipolar disorder, a disease that produces oscillatory behavior between inappropriate “highs” and the blackest of depressions. Although its exact function remains unknown, lithium seems to moderate the levels of neurotransmitters (compounds that are essential to nerve function), thus relieving some of the extreme emotions in sufferers of bipolar disorder.

In addition, a chemist named William Walsh has done some very interesting studies on the inmates of Stateville Prison in Illinois. By analyzing the trace elements in the hair of prisoners, he has found intriguing relationships between the behavior of the inmates and their trace element profiles. For example, Walsh found an inverse relationship between the level of cobalt in the prisoner’s body and the degree of violence in his behavior.

Besides the levels of trace elements in our bodies, the various substances in the water, the food we consume, and the air we breathe also are of great importance to our health. For example, many scientists are concerned about our exposure to aluminum, through aluminum compounds used in water purification, baked goods and cheese (sodium aluminum phosphate acts as a leavening agent and also is added to cheese to make it softer and easier to melt), and the aluminum that dissolves from our cookware and utensils. The effects of exposure to low levels of aluminum on humans are not presently clear, but there are some indications that we should limit our intake of this element.

Another example of low-level exposure to an element is the fluoride placed in many water supplies and toothpastes to control tooth decay by making tooth enamel more resistant to dissolving. However, the exposure of large numbers of people to fluoride is quite controversial—many people think it is harmful.

The chemistry of trace elements is fascinating and important. Keep your eye on the news for further developments.

See Problem 4.6