Lesson 2: Materials Created

from Chemical Changes

In the previous lesson, you learned about matter and some of its chemical and physical states and properties. But why should anyone care about these concepts?

When you think about it, you can likely see that there actually are many useful ways to apply knowledge about matter to the world. For example, if you know the properties of a particular substance, you can recognize it when you see it, even if you find it in a new or unusual place. Similarly, if you find a new substance, you can compare its properties to those of other substances you know more about. This might help you to figure out what kind of substance it is and help you think of ways to use the new substance.

New substances are being discovered and invented all the time, but people have been learning about matter for thousands of years. The Stone Age refers to a time about 10,000 years ago when people worked with simple stone tools. After these people discovered fire, they were able to create a greater variety of tools to suit their needs. As time passed, people discovered metals such as gold, copper, tin, iron, lead, and mercury and experimented with their properties to find uses for these metals as tools, utensils, jewellery, and weapons.

In this lesson, you will learn about the different materials that can be created from a relatively small number of components. You will also learn about technologies based on chemical change that are widely used in producing helpful materials for our daily lives.