All organisms in a community affect each other in some way, but people have a more lasting effect on their community than any other organisms. People add pollution to the environment which may destroy the habitat of other organisms. They may also be poisoned by the pollution. This chapter reviews some of the ways in which people affect the environment and ways to keep from damaging the environment. All objects are made of matter.
Matter takes up space and has mass.
The amount of space matter takes up is its volume. Mass is the measurement of how much matter an object has. There are many different kinds of matter, but they all have certain things in common. This chapter reviews the properties of matter, the particles that make up matter and the changes in matter. Forces A force is a push or a pull.