An exchange of one thing in return for another. Giving up something that is a benefit or an advantage, in exchange for something that may be more desirable. Always involve balancing benefits against risks.

The transfer of energy from one object to another.

The change of energy from one type to another, such as from potential to kinetic.

Energy stored due to an object’s mass and height.

Energy of motion.

Energy of position or stored energy.

A changing factor. In an experiment, this is what is studied, such as the effect of differing concentrations of salt on the growth of plants. The experiment would involve changing the salt concentration, while trying to keep all other factors the same.

A force that exists at the boundary between any two objects that are in contact with each other.

Energy that is transferred from a warm object to a cooler object.

The movement of thermal energy from hot to cold.

A device that converts electrical energy into mechanical energy.

A measure of molecular motion, generally using a Celsius (°C) or Fahrenheit (°F) scale; a measure of the average energy per molecule of a substance.

The ratio of useful energy that is released by a process to the total energy absorbed by the process; useful energy released: total energy absorbed.

The scientific law that states that energy can be transferred or transformed but it cannot be lost or destroyed.

A statement explaining a natural phenomenon that has been proven to occur repeatedly, whenever certain conditions exist.

A type of potential energy where the energy is stored in the bonds of atoms.

Potential energy that is stored by stretching or compressing.

Energy stored by the buildup of charge (electrons or ions).

A type of kinetic energy that is transferred by the rapid movement of electromagnetic fields.

A type of potential energy that is stored in the nucleus of an atom.<br />

A form of energy that is transferred through air, water, and many solid materials by the vibration of an object.

The flow of heat, electricity, or sound through a material.

A standard of comparison for checking or verifying the results of an experiment. In an experiment a single variable is changed to see if it has any effect on something being tested, but no variable is changed for this. The results of what happened to the thing that was subject to the variable are compared to this in order to see if the variable had any effect.

A material that is used to slow down or prevent the flow of heat or electricity through it.

A measure (unit) of heat energy. Specifically, it is the amount of energy needed to raise one gram of water one degree Celsius.

A device that measures the amount of chemical potential energy in a material.

A chemical reaction characterized by the absorption of heat.

A chemical reaction characterized by the production and release of heat. See endothermic reaction.

A property that, in your opinion, is good.

Material from living things, such as plants and animals, that is used as a source of fuel.

A property that, in your opinion, is not good.

Any one of several types of energy that is transformed into electricity.

A fuel produced when living plant materials have been buried and changed by heat and pressure under layers within the earth over millions of years of time. Natural gas, petroleum, and coal are examples

A machine for making electricity, generally by the circular movement of a turbine, driven by steam or water, connected to a magnet that revolves inside another magnet. When a magnet moves inside another magnet, an electric current results. This current can be transmitted for immediate use, or stored for later use.

The system in which energy is generated by moving water that turns the blades of a turbine, which generates electricity.

Energy obtained from such sources as fossil fuels and uranium ores. Once used, these sources are no longer available to furnish energy.

A facility that transforms energy into electricity and distributes it to the surrounding area.

A source of material that can easily be produced again and again in nature, such as wood, solar, and hydroelectric power, and food crops.

Energy that comes from the Sun.

Any of many machines that use kinetic energy from the movement of wind, water, steam, or gas to generate mechanical energy. It is made of paddles, buckets, or blades attached to a wheel that turns to produce mechanical energy. It also drives electric generators that transform mechanical energy into electrical energy.

Energy from the wind that causes a turbine to turn in order to generate electricity.

A device that provides electrical energy. It contains two or more chemical cells that generate a direct current through a chemical reaction.

a device that transforms stored chemical (potential) energy to electrical energy. A common example is a standard 1.5-volt battery used in flashlights, radios. cameras, etc.

A solution or pure liquid substance that forms ions to conduct an electrical current.

Magnetism associated with moving electrical charges.

A way of describing how two objects can interact with one another without touching.

The original substances that are present at the beginning of a reaction.

A path along which electrical energy can transfer.

A material or device that conducts or transmits heat, electricity, or sound.

A circuit in which the components are set up so that the electrical energy has more than one conducting path from the electrical source.

A circuit in which the components of the circuit are connected in succession to the power source so there is only one path for the electrical energy in the circuit.<br />

A bulb or tube for lighting in which electrical energy causes a gas inside the bulb or tube to emit visible light energy.

Describing light that is produced by a hot object. This uses a filament that is heated by the flow of an electrical current.

The unit of power that is one joule per second.

Materials such as solar cells made from silicon that produce an electrical current when exposed to sunlight.

Using the Sun as the source of energy in a heating system. An example is allowing sunlight on south-facing sides of a house to enter the house through windows to heat the house in winter.

To take in or to take up.

To bounce light off an object or material.

The light that is bounced off of an object or material.

The act of energy passing through a medium.

To permit or cause energy to pass through a medium.

A structure whose design takes advantage of existing energy features. For example, the structure may be open to the sun in the winter for heat but shaded in the summer. It may be situated on a lot with windows that allow breezes to circulate through the house. It may be built partially underground to reduce heating and cooling costs, etc.