Beginning of Essay
Mass is the amount of matter in an object. When you record mass the unit you use is grams. A medium sized leaf is about 1 gram, a potato chip 2 grams. A larger unit of mass is a kilogram. A kilogram is about the mass of a medium sized textbook. You need a balance ....

Middle of Essay
.... is the smallest unit of matter that can exist and still be recognized. You and all the things around you are made of matter. Since we all live at the surface of the earth where the acceleration of gravity is relatively constant, it has been natural for us to confuse the concepts of mass and weight. To study the difference, we need to separate these two "parameters." We could either leave the earth's gravitational field so that we would have no weight, or create an experimental situation where weight is not a factor. An easy way to do this is to use floating objects. Floating objects still have all their mass, and move almost friction-free in still wa ....