(5-8) H2

Science Curriculum Preview Committee Clarification of Learning Results

Revised 06/29/04

5-8

H2: Demonstrate that energy cannot be created or destroyed but only changed from one form to another.

Curriculum Organizing Questions

How is energy changed in this system?

Where does the energy in this system come from? Go to?

Where is heat lost in this system?

Does the sun provide energy for this system, either directly or indirectly?

Elaboration
The idea of transformations should remain qualitative at this level. The intent should be to help students improve their understanding of energy by experiencing many forms of energy transformation. The idea of energy transformation may be a more important idea than the idea of energy itself. All physical events involve transferring energy or changing one form of energy into another--radiant to electrical, chemical to mechanical, and so on. So might the idea that whenever there is a transformation of energy, some of it is likely to go into heat, which spreads around and is therefore not available for use.Benchmarks pgs. 81- 82 & 84.

Specific Ideas

Energy is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical.NSES B3a.

Energy can change from one form to another, although in the process some energy is always converted to heat. Benchmarks 8C1.

Most of what goes on in the universe--from exploding stars and biological growth to the operation of machines and the motion of people--involves some form of energy being transformed into another.Benchmarks 4E2.

Whenever energy in one place decreases, energy in other places increases by the same amount.Benchmarks 4E1 (9-12).

The sun is a major source of energy for changes on the Earth's surface. The sun loses energy by emitting light. A tiny fraction of that light reaches the earth, transferring energy from the sun to the earth. NSES B3f.

Developmental & Instructional Implications
Performance indicator H (5-8) #2 should be taught prior to H (5-8) #1.

The idea of energy conservation seems counterintuitive to middle and high school students. Even after instruction students may not see energy conservation as a useful way to explain phenomena. Benchmarks p. 338.

Research suggests that middle and high school students tend to think that energy transformations involve only one form of energy at a time. Although they develop some skill in identifying different forms of energy, in most cases their descriptions of energy change focus only on forms that have perceivable effects. The transformation of motion to heat seems to be difficult for students to accept, especially in cases with no obvious temperature increase. Finally, it may not be clear to students that some forms of energy, such as light, sound, and chemical energy, can be used to make things happen. Benchmarks p. 338.

Systems thinking is essential to mastery of this performance indicator. See Benchmarks pages 261-265 for a discussion of the development of systems ideas.

See pages 143-147 in Driver et al for a detailed description of children's ideas about energy.

Examples

Back to Big Ideas Grid H Back to Standard H Back to Index

Curriculum Organizing Questions	How is energy changed in this system? Where does the energy in this system come from? Go to? Where is heat lost in this system? Does the sun provide energy for this system, either directly or indirectly?
Elaboration	The idea of transformations should remain qualitative at this level. The intent should be to help students improve their understanding of energy by experiencing many forms of energy transformation. The idea of energy transformation may be a more important idea than the idea of energy itself. All physical events involve transferring energy or changing one form of energy into another--radiant to electrical, chemical to mechanical, and so on. So might the idea that whenever there is a transformation of energy, some of it is likely to go into heat, which spreads around and is therefore not available for use.Benchmarks pgs. 81- 82 & 84.
Specific Ideas	Energy is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical.NSES B3a. Energy can change from one form to another, although in the process some energy is always converted to heat. Benchmarks 8C1. Most of what goes on in the universe--from exploding stars and biological growth to the operation of machines and the motion of people--involves some form of energy being transformed into another.Benchmarks 4E2. Whenever energy in one place decreases, energy in other places increases by the same amount.Benchmarks 4E1 (9-12). The sun is a major source of energy for changes on the Earth's surface. The sun loses energy by emitting light. A tiny fraction of that light reaches the earth, transferring energy from the sun to the earth. NSES B3f.
Developmental & Instructional Implications	Performance indicator H (5-8) #2 should be taught prior to H (5-8) #1. The idea of energy conservation seems counterintuitive to middle and high school students. Even after instruction students may not see energy conservation as a useful way to explain phenomena. Benchmarks p. 338. Research suggests that middle and high school students tend to think that energy transformations involve only one form of energy at a time. Although they develop some skill in identifying different forms of energy, in most cases their descriptions of energy change focus only on forms that have perceivable effects. The transformation of motion to heat seems to be difficult for students to accept, especially in cases with no obvious temperature increase. Finally, it may not be clear to students that some forms of energy, such as light, sound, and chemical energy, can be used to make things happen. Benchmarks p. 338. Systems thinking is essential to mastery of this performance indicator. See Benchmarks pages 261-265 for a discussion of the development of systems ideas. See pages 143-147 in Driver et al for a detailed description of children's ideas about energy.
Examples