Michigan Science
Standard VI.1 Matter and Energy: All students will
measure and describe things around us; explain what the world around us is made
of; identify and describe forms of energy; and explain how electricity and
magnetism interact with matter.
Elementary Benchmark 6:
Describe interaction of charged materials with other charged or uncharged
materials.
Elementary Benchmark 7:
Describe possible electrical hazards to be avoided at home and at school.
3. Technology
productivity tools
·
Use general purpose productivity tools and
peripherals to support personal productivity, remediate skill deficits, and
facilitate learning throughout the curriculum.
4. Technology
communications tools
·
Use technology tools (e.g. multimedia authoring,
presentation, Web tools, digital cameras, scanners) for individual and
collaborative writing, communication, and publishing activities to create
knowledge products for audiences inside and outside the classroom.
Objectives:
1. Students
will understand that electric current is controlled and directed by circuits
made of conductors, insulators, current sources and resistors.
2. Students
will identify possible safety hazards associated with electricity and how to
avoid these hazards.
·
1 D cell battery
·
1 light bulb
·
1 bulb holder
·
4 wires
Imagine that you wake up
one day and there is a power outage, there is no electricity at all. What
effect would that have on our lives? (Heat, light, cooking, energy for
appliances) Think beyond your own life, how would a power outage affect
hospitals, businesses and other people? We use electricity from the time we get
up, awakened by an alarm clock, to the time we go to bed. Have you ever stopped
to think how electricity travels? When you flip a switch on the wall, why does
the overhead light go on?
Today you will work in groups of four. Each group of four will receive: 1 battery, 1 light bulb, 1 bulb holder, and 4 wires. Your job is to make the bulb light up. When you find a way that works, draw a picture of it on your worksheet. Can you find more than one way to make it light? After all the groups have made the bulb light up, we will come together as a class to discuss what we discovered. You have built a circuit, which is a pathway for electricity to travel through. (At this point, you may want to stop the students and discuss the information in Part 1 of the develop section.)
Next, I want you to try adding things to your circuit. Will electricity travel through all materials? Choose some objects from around the room. On your worksheet, write down the object and your prediction as to whether the light bulb will light up or not when that object is added to the circuit. After you have written down a prediction, test these objects and write down the results. What objects did you test? What did you find when these objects were added to your circuit?
As
I mentioned earlier, electricity travels through a path called circuit.
To make a circuit, we need these three things: a current source, a path for
electricity to travel through, and something to receive the electricity. In our
experiment, the battery was the current source; it served as a source of energy
for the light bulb. The wires provided a path for the energy from the battery.
The light bulb acted as a receiver for the energy, when the energy arrived at
the bulb, it lit up. There are two kinds of circuits – open and closed. A closed
circuit has no breaks in it so the flow of energy is not interrupted and
the current flows continuously. A circuit with a break in it is called an open
circuit. An open circuit will not allow for a continuous current flow and
will not work. If you have an open circuit, the bulb will not light.
When
you added things to your circuits, sometimes the bulb lit up and sometimes it
did not. What were some of the things you tested that worked? These objects are
called conductors, they allow electricity to pass through them. In
general, what kinds of materials conducted electricity? (Metals) What were some
of the things that did not work? Objects that do not allow electricity to flow
through them are called insulators. Generally, materials that are
non-metals do not allow electricity to flow through them.
As we have discussed,
electrical energy is widely used throughout the world today. We have been
concentrating on the positive uses of electricity, but can you think of some
ways that electricity may be harmful? What are some ways that you can stay safe
around electricity? Have the students list at least 5 electrical hazards, at
home or school, and how they can be avoided.
Adapted from: Electrical Energy published Macmillan/McGraw-Hill School Publishing Company, 1993.