# Matter & Energy Chapter 1 (Notes + Flashcards)

All objects are made of matter.

Suppose your class takes a field trip to a museum. During the course of the day you see mammoth bones, sparkling crystals, hot-air balloons, and an astronaut’s space suit. All of these things are matter. Matter is what makes up all of the objects and living organisms in the universe. As you will see, is anything that has mass and takes up space. Your body is matter. The air that you breathe and the water that you drink are also matter. Matter makes up the materials around you. Matter is made of particles called atoms, which are too small to see. You will learn more about atoms in the next section. Not everything is matter. Light and sound, for example, are not matter. Light does not take up space or have mass in the same way that a table does. Although air is made of atoms, a sound traveling through air is not.

Mass is a measure of the amount of matter. Different objects contain different amounts of matter. MATTER- is a measure of how much matter an object contains. A metal teaspoon, for example, contains more matter than a plastic teaspoon. Therefore, a metal teaspoon has a greater mass than a plastic teaspoon. An elephant has more mass than a mouse.

Measuring Mass When you measure mass, you compare the mass of the object with a standard amount, or unit, of mass. The standard unit of mass is the kilogram (kg). A large grapefruit has a mass of about one-half kilogram. Smaller masses are often measured in grams (g). There are 1000 grams in a kilogram. A penny has a mass of between two and three grams. How can you compare the masses of two objects? One way is to use a pan balance, as shown below. If two objects balance each other on a pan balance, then they contain the same amount of matter. If a basketball balances a metal block, for example, then the basketball and the block have the same mass. Beam balances work in a similar way, but instead of comparing the masses of two objects, you compare the mass of an object with a standard mass on the beam.

Measuring Weight

When you hold an object such as a backpack full of books, you feel it pulling down on your hands. This is because Earth’s gravity pulls the backpack toward the ground. Gravity is the force that pulls two masses toward each other. In this example, the two masses are Earth and the backpack. is the downward pull on an object due to gravity. If the pull of the backpack is strong, you would say that the backpack weighs a lot. We ight is measured by using a scale, such as a spring scale like the one shown on the right, that tells how hard an object is pushing or pulling on it. The standard scientific unit for weight is the newton (N). A common unit for weight is the pound (lb). Mass and weight are closely related, but they are not the same. Mass describes the amount of matter an object has, and weight describes how strongly gravity is pulling on that matter. On Earth, a one-kilogram object has a weight of 9.8 newtons (2.2 lb). When a person says that one kilogram is equal to 2.2 pounds, he or she is really saying that one kilogram has a weight of 2.2 pounds on Earth. On the Moon, however, gravity is one-sixth as strong as it is on Earth. On the Moon, the one-kilogram object would have a weight of 1.6 newtons (0.36 lb). The amount of matter in the object, or its mass, is the same on Earth as it is on the Moon, but the pull of gravity is different. Volume is a measure of the space matter occupies. Matter takes up space. A bricklayer stacks bricks on top of each other to build a wall. No two bricks can occupy the same place because the matter in each brick takes up space. The amount of space that matter in an object occupies is called the object’s The bowling ball and the basketball shown on page 10 take up approximately the same amount of space. Therefore, the two balls have about the same volume. Although the basketball is hollow, it is not empty. Air fills up the space inside the basketball. Air and other gases take up space and have volume.

`End of Lesson 1`