# 2.9: Elements

### Introduction

The famous fictional British detective Sherlock Holmes was often said to make the statement "elementary, my dear Watson". In reality, the closest he ever came to that line was an exchange with Watson in the short story "The Crooked Man". Holmes shows shrewd insight into Watson's activities of the day. When asked how he knew what Watson was doing, Holmes simply replies "Elementary". Regardless of exactly how he put it, Sherlock was simply referring to what the Free Dictionary defines as "relating to, or constituting the basic, essential, or fundamental part".

### Elements

An element is the simplest form of matter that has a unique set of properties. Examples of well-known elements include oxygen, iron, and gold (see below). Elements cannot be broken down into a simpler substance. Likewise, one element cannot be chemically converted into a different element.

Chemical elements are the simplest of substances. (A) An oxygen tank like this is used by people with a need for breathing assistance. (B) A simple skillet can be made from cast iron. (C) Gold bars are formed and used for monetary purposes.

Some elements have been known for centuries (gold, silver, iron, and copper among others) while others have been created in the lab only within the last several years. Most elements do not exist as such in nature. They are so reactive that they can be found only in combination with other materials.

Several of the elements are very valuable while others are quite inexpensive. Gold is currently worth almost $1700 per ounce. Aluminum, on the other hand, only sells for about 90 cents per pound, considerably lower than gold. Copper is worth somewhat more, selling for approximately$3.50 per pound. Platinum is very valuable at about \$1650 an ounce, not quite as expensive as gold.

### Summary

• An element is the simplest form of matter that has a unique set of properties.
• One element cannot be chemically converted to another element.

### Explore More

Select five elements from this interactive Periodic Table