• 9-12: 4E/H5. When energy of an isolated atom or molecule changes, it does so in a definite jump from one value to another, with no possible values in between. The change in energy occurs when light is absorbed or emitted, so the light also has distinct energy values. The light emitted or absorbed by separate atoms or molecules (as in a gas) can be used to identify what the substance is.
• 9-12: 4E/H7. Thermal energy in a system is associated with the disordered motions of its atoms or molecules. Gravitational energy is associated with the separation of mutually attracting masses. Electrical potential energy is associated with the separation of mutually attracting or repelling charges.
• 9-12: 4E/H9. Many forms of energy can be considered to be either kinetic energy, which is the energy of motion, or potential energy, which depends on the separation between mutually attracting or repelling objects.

• 6-8: 4F/M6. Light acts like a wave in many ways. And waves can explain how light behaves.

• 9-12: 4G/H2b. At the atomic level, electric forces between electrons and protons in atoms hold molecules together and thus are involved in all chemical reactions.
• 9-12: 4G/H8. The motion of electrons is far more affected by electrical forces than protons are because electrons are much less massive and are outside of the nucleus.

• 6-8: 11B/M1. Models are often used to think about processes that happen too slowly, too quickly, or on too small a scale to observe directly. They are also used for processes that are too vast, too complex, or too dangerous to study.

• F-IF.6 Calculate and interpret the average rate of change of a function (presented symbolically or as a table) over a specified interval. Estimate the rate of change from a graph.

• RST.11-12.1 Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account.
• RST.11-12.2 Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms.

• RST.11-12.4 Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 11—12 texts and topics.

• RST.11-12.10 By the end of grade 12, read and comprehend science/technical texts in the grades 11—CCR text complexity band independently and proficiently.

• 1. Write arguments focused on discipline-specific content. (WHST.11-12.1)

Help your students visualize what's going on when atoms undergo "excitation" and emit wave packets of light called photons. This set of classroom-tested computer simulations is highly recommended for promoting understanding of atomic processes in photon emission. Teachers: free registration allows your students to capture data, take snapshots, and submit work.

• Algebra-Based Physics Renewable Energy Sources Unit
• AP/Calculus-Based Physics Renewable Energy Sources Unit