Types of Energy What is Energy? Energy is all around us. But what, exactly, is energy? Energy makes change possible. We use it to do things for us. It helps us heat our homes and move our cars. It allows us to listen to music and to dance to it! Energy is what makes our bodies grow and lets our minds think. It s how plants make food, and how animals eat and use that food. In science, energy is defined as anything that makes matter move or change. (Matter is anything that has mass and volume things you can touch, such as wind, water, rocks, air even you are made of matter!) Without energy, matter on Earth would not be able to move around or to change. When energy makes matter move, that is called doing work. In science class, work is when a force (energy) makes an object move. So, energy is doing work making objects move or change. Pushing the wheelbarrow is doing work! Forms of Energy There are many forms (or types) of energy, but they all have one thing in common they make matter move or change. Different forms of energy work and move in different ways. Energy can move from one place to another, or from one thing to another. Energy can even transform, or change from one type to another type. We will be learning about energy changes in another lesson. For this lesson, you need to know about 6 types of energy: light, heat, sound, electric, mechanical, and chemical.
Light Energy (also called radiant energy) Light energy is actually just one part of what is called electromagnetic energy, which comes from the Sun. Electromagnetic energy moves in waves. It can travel through solids, liquids, gases even empty space. These waves of energy make up what is called the electromagnetic spectrum. Examples of different waves in the electromagnetic spectrum include: visible light, x-ray, radio waves, microwave, infrared light, and ultraviolet light. Each type of electromagnetic wave is a different size (frequency). Light is just one size of wave on the electromagnetic spectrum. Light is also called radiant energy. The Electromagnetic Spectrum Visible light is actually a very small part of the electromagnetic spectrum, but it is very important. Light from the Sun changes into heat. Light helps us to see, and gives plants energy to make food (photosynthesis). Examples of light energy include: a flashlight, light from a campfire, and of course light from the Sun. Thermal (Heat) Energy Thermal energy also called heat energy is the energy of moving molecules. All matter is made of molecules, which are made of tiny things called atoms. When molecules are exposed to thermal energy, the energy makes them move. As they receive more thermal energy, they move faster and faster. As objects lose heat energy (get cooler), the molecules inside them slow down. The molecules with more heat energy are moving faster.
Heat can move by flowing from one place to another. That is how you feel heat from the oven when you are standing a few feet away. Heat can also move easily from one thing into another thing. This is how the frying pan heats up your egg! There are many examples of heat heat from a campfire, heat from a hot oven, heat from inside the Earth there is even heat inside you! Sound Energy Sound energy is the energy of vibrations. Right now place your hand on your throat, and say something. Do you feel the vibrations? Sound can travel from place to place through these vibrations, which are also called sound waves. If you ve ever felt the top of a speaker, you can feel it vibrating. The vibrations, or sound waves, are how the sound travels from the speakers to your ears. Sound waves can travel through solids, liquids or gases. But sound cannot travel through empty space. You can t hear sound in outer space! Sound waves Electrical energy Electrical energy is caused by tiny charged particles, called electrons. These electrons move in a current so that electricity can move from one place to another (usually through a wire). Electrical currents move in what is called a circuit. Many, many things that we use require electricity. Luckily, many types of energy can be converted (or changed) into electricity. We can use solar energy, moving energy from wind or water, or chemical energy from fuel to make electricity. Your refrigerator, stove, and television set use electricity to work. Lightning is one form of natural electricity.
Mechanical Energy Mechanical energy is the energy of moving things. When you walk across the room, you are demonstrating mechanical energy. If something is moving, it has mechanical energy. Examples of mechanical energy are flowing water, blowing wind, spinning wind turbines, or a moving car. Mechanical energy can be easily transferred from one object to another. If you kick a soccer ball, you are transferring the mechanical energy from your moving foot into the ball, which begins moving. Mechanical Energy Chemical Energy Chemical energy is energy that is stored inside something, waiting to be used. A battery is an example of chemical energy. The battery has chemical energy inside of it. When you hook wires to the battery and turn it on, the chemical energy inside the battery is changed into electrical energy. When all of the chemicals are used up, the battery no longer has energy. Fuel is another example of chemical energy. Wood has chemical energy inside of it. When you burn wood, the chemical energy is converted into light and heat energy. One last example of chemical energy is food. When you eat food, the chemical energy inside the food is changed into energy that your body needs to do stuff! Chemical energy doesn t really move, because it is stored inside, waiting to be used. Chemical Energy
Review: Here are the 6 types of energy you need to know: Light (radiant) energy energy that moves in waves; it helps you see and lets plants make food Heat energy energy of moving molecules inside of things, that flows from place to place Sound energy energy of vibrations that move in waves Electrical energy energy from electrons, that flows in a current Mechanical energy energy in anything that is moving Chemical energy stored energy inside of something, like a battery or food or fuel