CK-12 Physical Science Concepts - For Middle School

(Marvins-Underground-K-12) #1

5.67. Chemical and Solar Cells http://www.ck12.org


Summary



  • Current requires a source of voltage, which is a difference in electric potential energy. Sources of voltage
    include chemical cells and solar cells.

  • Chemical cells are found in batteries. They produce voltage by means of chemical reactions. They contain
    electrodes and an electrolyte, which may be a paste (dry cell) or a liquid (wet cell).

  • Solar cells convert the energy in sunlight to electrical energy. They contain a material such as silicon that
    absorbs light energy and gives off electrons.


Vocabulary



  • chemical cell: Source of voltage found in batteries that consists of two electrodes suspended in an electrolyte
    and produces voltage by chemical reactions.

  • solar cell: Source of voltage that converts the energy in sunlight to electrical energy; also called photovoltaic
    cell.


Explore More


Launch the interactive at the following URL to learn more about solar cells. Then answer the questions below. http
://www.pbs.org/wgbh/nova/tech/how-solar-cell-works.html



  1. Why does a solar cell have an antireflective coating?

  2. How is the silicon in a solar cell “doped” so it will conduct electricity?

  3. Explain how an electric field is established in the solar cell.

  4. Describe how photons from the sun affect the silicon layers of a solar cell.

  5. What parts of a solar cell conduct electricity into a wire so it can be used for electric devices?


Review



  1. What is voltage? How is it related to electric current?

  2. How does a chemical cell produce current?

  3. Explain how a solar cell works.

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