Is air matter?

Matter is an important scientific term. You will use the word matter often in studying the units that follow. ‘-Matter is the general name that is given to all substances of any sort. Matter is anything that takes up space and has weight: Thus you are matter because you take up space and have weight. A dog, the things you eat, the clothes you wear, and all the things that can be seen or handled are matter.

You can see that a book takes up space, and if you pick it up, you know that it has weight. But are substances that you cannot see matter? For example, is air matter? Does air have weight and does it take up space, as a book does? Air has weight and takes up space. Hence air is matter just as truly as you.