Chemistry Basics

• Understand the various energy levels of electrons.
• Define wavelength.
• Define photon.
• Be able to interpret the electromagnetic radiation spectra chart.
• Understand that the visible light spectra demonstrates a variety of energy levels.
• Perform a flame test.

Electrons jump around within an atom as they either gain or lose energy. When an electron is hit by a photon of light for example, it absorbs the energy the photon was carrying and moves to a higher energy state. Then, at some point, these higher energy electrons give up their “extra” energy in the form of a photon of light, and fall back down to their original energy level. The light that has suddenly been produced rushes away from the electron and c an be seen as light or color. This property of electrons, and the energy they absorb or give off, can be put to an every day use. In todays lab, students will study the electromagnetic spectrum and understand how electrons absorb or lose energy. Students will perform a flame test to show how energy is released as various colors.

1. Start off with 360 firework field trip and explain how the colors are related to energy and what we will be discussing in class.
2. Define energy and the different types.
3. Explain e- and how they move through different orbitals.
4. Show them the electromagnetic spectrum and explain the differences in wavelengths and energy.
5. Explain the visible spectra and why different colors can be seen in a flame test.
6. Show video explaining light emission test.
7. Perform flame test. It is available in the chemistry lab area. results below in ancillary section.
8. Emphasize that the metal in the compound determines color of flame.
9. Have students predict wavelengths based on colors.

Firework video: https://www.youtube.com/watch?v=WDGxepzOiLE   Metal flame emission explanation: https://www.jove.com/science-education/11162/metal-flame-emission Flamer test lab results: cesium chloride (blue), barium chloride (green), cupric chloride (blue green), strontium chloride (red), potassium chloride (purple), lithium chloride (red), sodium chloride (yellow), calcium chloride (orange)