An element is a substance that cannot be separated into two or more substances.
Carbon and iron are examples of elements. Compare a bit of charcoal, which is one form of carbon, with a new iron nail. Which is brighter ? Heavier for its size ?
Tougher ? More brittle ? Harder ? More readily combustible ? Resistant to change when left exposed to air and dampness ? There are two other forms of carbon : graphite or black lead (used in pencils and stove polish); and diamond, which occurs in crystals and is the hardest known substance. Iron does not have varied forms like carbon. Sulfur is another element. What is its color? Has it odor? Taste? Will it dissolve in water? Is it heavy or light ? Will it burn ? What is the color of the flame ? Of the fumes ? Phosphorus, another element, burns so readily that it ignites by friction and is used in matches. Rub the tip of a match with the finger. What is the odor of phosphorus ? Phosphorus exists in nature only in combination with other elements. Lead, tin, silver, gold, copper, zinc, nickel, platinum, are elements.
There are less than two hundred elements ; but the compounds formed of them are innumerable. Carbon is found in all substances formed by the growth of living things.
That there is carbon in sugar, for example, can easily be shown by charring it on a hot shovel or a stove until its water is driven off and only charcoal is left. Part of the starch in a biscuit remains as charcoal when it has been half burned.
