Energy

Unit Review Sheet

Facts and Definitions

Lesson 1: Introduction to Energy and Matter

• Energy is the ability to do work.
• Matter is anything that takes up space (has volume). Mass is how we measure matter; it is the amount of matter in an object or substance.
• There are many different forms of energy. These forms, or types, of energy have different different characteristics and are found in different situations. Potential energy, kinetic energy, nuclear energy, and sound energy are some of the different forms energy can take.
• An energy source is something with stored energy that can be transformed into usable energy. Coal, wood, wind, and water are examples of energy sources.
• Renewable energy is continuously being made by nature in a reasonably short amount of time; nonrenewable energy will eventually run out because it takes a long time for nature to produce.
• Mechanical energy is energy caused by the physical movement of matter or by its potential to move.
• Thermal energy is the movement of atoms and molecules, producing heat.
• An electromagnetic wave is energy that can travel through space and has wave-like behaviors.

Lesson 2: Energy Transfer

• Mass is how we measure matter; it is the amount of matter in an object or substance.
• According to the law of conservation of energy, energy is not created or destroyed; energy can only be transformed into different forms of energy (such as from potential to kinetic) or transferred between objects.
• According to the law of conservation of mass (or matter), matter is not created or destroyed. Matter can change forms (such as from a solid to a liquid, or from a water molecule to individual atoms of hydrogen and oxygen), but the total amount of matter remains the same.

Lesson 3: Electricity

• Energy carriers transfer energy in a usable form to where it is needed. Electricity and hydrogen are both energy carriers.
• Electricity is the movement of charged particles. It is caused by electrons going from one atom to another. When electrons build up in one spot, electricity appears as a static shock or lightning. When electrons flows along a path (such as a wire), it is called an electrical current.
• Electricity must be in a circuit in order to flow as a current. A circuit is like a complete path or loop that electricity can follow.
• Magnetism is the phenomenon of physical attraction for iron, present in magnets or stimulated by a moving electric charge or current.
• An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current.
• Electromagnetic induction is the process of generating (inducing) electricity by using magnetism.
• A turbine is a machine that turns when force is applied to it.

Lesson 4: Radiant Energy

• Electromagnetic radiation is energy in the form of visible, infrared, or ultraviolet light; other forms of electromagnetic radiation exist, including x-rays, microwaves, and radio waves.
• Electromagnetic waves are forms of energy that travel through space and have wave-like behaviors.
• A photon is an energy particle from the Sun.
• Solar energy is energy that comes from the Sun (in the form of visible light and other electromagnetic waves).
• Photovoltaic cell is another name for the parts of a solar panel. A solar panel has different layers and different materials that enable it to collect the sun's solar energy.
• A semiconductor is a solid material that conducts electricity.

Lesson 5: More Renewable Power Sources

• Wind energy is energy produced by the movement of air.
• Hydropower is energy produced by the movement of water.
• Geothermal energy is heat energy from below the Earth's surface.

Lesson 6: Nuclear Power

• Nuclear fusion is the process of combining ("fusing") two lighter atoms to create one new heavier atom.
• Nuclear fission is the process of splitting an atom apart. The energy produced from the fission of uranium (or plutonium) atoms can be used to generate electricity.
• A nuclear power plant uses a controlled chain reaction of atoms being split to generate electricity. Control rods absorb some of the released neutrons to prevent too many atoms from being split.

Lesson 7: Fossil Fuels and Biomass

• Natural gas and petroleum (also called oil) both formed at the bottom of oceans from decaying plants and animals. Gradually the plants and animals were buried in mud and rock, and the heat and pressure transformed them into the fuels we use today.
• Peat is formed from layers of partially-decayed plants in marshlands and bogs. If left alone for millions of years under heat and pressure, it would turn into coal.
• Biomass is organic material from plants and animals that can be used as fuel. Peat, wood, cow manure, paper, and food scraps are examples of biomass fuel sources.

Lesson 8: Powering Our World

• A power grid coordinates the flow of electricity from where it is produced (at power plants) to where it is consumed (at houses, businesses, and industrial sites).
• Electricity is produced on-demand and must be carefully managed in order to balance supply and demand.
• Power plants are limited by the resources available to them to produce electricity. For example, cities far from rivers or bodies of water cannot use hydropower.

Final Project: Energy Conservation

• Conservation is the protection, supervision, and care of natural resources.