Compounds and Mixtures — Reading Comprehension Lesson

Reading Passage

Compounds and Mixtures

All matter is made of tiny particles called atoms. Atoms can join together in different ways to form many of the substances we see and use every day. Two important kinds of substances that result from atoms combining are called compounds and mixtures.

A compound is formed when two or more different elements bond chemically to make a brand-new substance. The new substance has properties that are very different from the elements that made it. For example, water is a compound made from hydrogen and oxygen. By themselves, hydrogen and oxygen are gases, but together they form a liquid we drink every day.

Salt is another familiar compound. It is made from sodium, a soft silvery metal that reacts violently with water, and chlorine, a poisonous green gas. When these two elements combine, they form sodium chloride — ordinary table salt — which is safe to eat and helps flavor our food. Once a compound is made, the only way to break it apart is through a chemical reaction.

A mixture is different from a compound. In a mixture, two or more substances are combined, but they do not react chemically. Each substance keeps its own properties and can usually be separated again by physical means like filtering, evaporation, or using a magnet.

Mixtures are everywhere in daily life. A salad is a mixture of lettuce, tomato, and other vegetables. Sand on a beach is a mixture of tiny rocks, shells, and minerals. Even the air around us is a mixture of gases including nitrogen, oxygen, and carbon dioxide. Understanding compounds and mixtures helps scientists describe the materials that make up our world.

Printable Worksheet

More Science Worksheets

Explore our full library of science reading comprehension worksheets and lesson resources.