Log In | Register

Key Idea: Energy can be moved from place to place through sounds, light, or electric currents.

Students should know that:

  1. Energy can be transferred by light when light from the light source shines on another object (receiver). For example, when a light bulb (or the sun) shines light on an object, energy is transferred from the light bulb (or the sun) to the object.
    1. The longer a light source shines on another object, the more energy is transferred from the source to the object.
    2. When an object absorbs light, the object gets warmer, (unless energy is transferred away from the object), which means the thermal energy of the object typically increases.  For example, when the sun shines on a person, the person’s body becomes warmer.  When an object gives off light, the object gets cooler, which means the thermal energy of the object typically decreases (unless additional energy is supplied to the light source (e.g. a lamp plugged into an electrical outlet)). For example, as a glowing hot piece of metal cools, some of the temperature decrease is due to the fact that light is being given off. [This sub-idea assumes that neither object changes state, in which case the temperature of the object would not increase or decrease.]
  2. Electrical sources, such as batteries or generators, can transfer energy to electrical devices, such as a light bulbs, speakers, heaters, or motors.
    1. The transfer of energy electrically can produce motion, sound, heat, or light.
  3. A vibrating object (such as a guitar string, a drum, or a tuning fork) can transfer energy to another object by producing sound that travels through a material such as air, water, or another solid object between the two objects.
    1. The louder the sound, the greater the amount of energy transferred.


  1. Students are not expected to know that all objects give off “electromagnetic radiation.”  This idea is limited to visible light.
  2. This idea is not quantitative. Assessment items do not ask students to calculate how much energy is transferred electrically in a particular situation (e.g. Power = current X voltage).
  3. Contexts of assessment items are limited to those that do not involve changes of state.
  4. Contexts used in items are limited to audible sound.

No misconceptions are associated with this idea in the selected project.

No NGSS statements are associated with this idea in the selected project.