Applied Science - Technology (4A)
Pre Lab 

   
OBJECTIVES:
  • Investigating the electronic industry.
  • Exploring semi-conductors.

VOCABULARY:

  • circuit
  • conductor
  • electronics
  • semi-conductor
MATERIALS:

Students look at the electronic industry.

BACKGROUND:

Emphasize that the study of electricity and magnetism revolutionized the world. Have students think about life without electricity. Ask them what would work without electricity. They will be surprised to see a very small list. In the next few labs, students will learn how magnetism, added to principles of electricity, has shaped our modern society. Students should be very familiar with the word "electronics". Electronics is the branch of science and engineering concerned with the theory, design, and use of devices utilizing electron emission or absorption. Electronics includes all aspects of photoelectric cells, transistors, circuits, cathode-ray tubes, electron tubes, oscilloscopes, electron microscopes, broadcasting, radio, television, telephone, and many other industries.

In 1883, Thomas Edison was studying a weakness in the filament of his newly developed incandescent lamp. He placed a strip of metal in the bulb and connected it to a battery. When the bulb was lighted, he found that electrons flowed from the filament to the metal strip even though there was no conductor between them. Edison did not continue to explore this phenomenon which later became known as the "Edison Effect". This can be attributed as the beginning of "electronics." Shortly after the beginning of this century, however, other scientists did perform experiments to learn more about the Edison effect. Foremost among them were an Englishmen, Sir John Fleming, and an American, Dr. Lee De Forest.

PROCEDURE:
  1. Make sure students realize that electronics deals with the movement of free electrons through semi-conductor materials which conduct electricity better than insulators (non-conductors) but not as well as conductors. Show students a complete chip board and tell them this is why it is called the " semi-conductor industry."
      
  2. If you have computer chips available, have students look under the microscope and see all the electrical circuits that are on that one chip.
      
  3. The main characteristic of all semiconductors is the resistance to allow electrons to flow. The reason for this is the crystalline structure of the material. The semiconductor industry must understand the crystal structure of the materials they use as semiconductors in order to predict how the electrons will flow to produce an electrical current. The common semiconductors are germanium and silicon, and to a smaller extent selenium and tellurium. In California, the infamous "Silicon Valley" is named for the most widely used semiconductor in computers
      
  4. Use the worksheet to have students write an essay on the electronics industry. If you live near a "technology area" you may want to emphasize that area. Otherwise you can have the students do a search on the Internet on different electronics company from chip makers, to computer manufacturers, or any other subjects they come up with. They may want to ask their parents or neighbors about this industry. If you have a parent in the industry, invite them to give a talk.

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