What is matter?

You have met many properties of materials: lustre, hardness, whether we can see through them, whether they dissolve. But not every material has every property: wood is not lustrous, and sawdust does not dissolve.

Two properties, though, belong to all materials: mass and volume. Everything has some mass, and everything takes up some space. An elephant does, and so does an ant.

Anything that takes up space and has mass is called matter.

Think of the three cups. The water is matter, the sand and pebbles are matter, and so is the cup. You are matter too. What about air? We cannot see it, but air is matter: it fills a balloon, and a blown-up balloon weighs a tiny bit more than an empty one. An apple is matter, because it takes up space and has mass. (Light, heat and electricity are not matter: they have no mass and take up no space.)

Materials are the kinds of matter used to make objects. Paper, wood, glass and metal are all matter, used to make notebooks, tables, tumblers and keys.