There are two types of pure substances. Elements are substances made of only one kind of atom. Oxygen, carbon, iron, potassium, aluminum, and helium are all examples of elements. There are 92 naturally occurring elements. Compounds are substances which are made from chemical combinations of two or more kinds of elements combined in definite amounts.
Table salt is compound made from the element sodium and the element chlorine.
Sugar is a compound made from the elements, carbon, hydrogen, and oxygen. Fats are a group of compounds which are made from the elements carbon, hydrogen, and oxygen in different amounts than found in sugar. In fact the thousands of compounds we know of are made by chemically combining varying amounts of the elements found on the periodic table. Compounds generally have properties very different from the elements which make them up. Return to the 8th Grade Integrated Science Sci-ber Text Page .