Conductors, Insulators and Semiconductors
Objectives
Ÿ Students will acquire a basic understanding of electrical conductors, insulators
and semiconductors.
Suggested Grade Level
7th grade
Subject Areas
Science
Industrial Technology
Timeline
Inquiry and discussion, one 45-minute class period
Hands-on activities, one to two 45 minute class periods
Writing assessment, to be completed as homework
Background Knowledge
Students need to have a basic knowledge of electricity and, how to conduct internet
searches to find specific information about a certain subject. Suggested websites
for the student internet searches are: http://www.howstuffworks.com,
http://www.google.com, http://www.ask.com, http://www.altavista.com Students need
to have the ability to read and follow instructions. Electronic kits must be ordered
ahead of time. A suggested web site is listed in the materials section below,
comparison-shopping is recommended.
Materials
Electronic project kit
http://www.abra-electronics.com/catalog/kits/eki_1101.html
Internet capable computers
Lesson
Day 1
1. Introduce the topics of our internet search; conductors, insulators and semiconductors. Ask students what they think would make a good conductor, insulator,
and also what they believe a semi-conductor might do.
2. Divide students into groups of 3 or so. Have these groups complete the
following internet search work sheet, see addendum. Allow 15 to 20 minutes for the
groups to complete their searches.
3. Bring students back together and discuss their findings. Ensure that all students
have the correct answers to the internet search questions.
Information Search
Conductors, Insulators and Semiconductors
Name_________________________________
1. What are electrical conductors?
________________________________________________________________
________________________________________________________________
________________________________________________________________
2. List the four materials that are good conductors
a.___________________________________
b. ___________________________________
c. ___________________________________
d. ___________________________________
3.
What
makes
a
good
conductor,
a
good
conductor?
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
4. What is an electrical insulator?
________________________________________________________________
________________________________________________________________
________________________________________________________________
5. Why is a good insulator a good insulator?
________________________________________________________________
________________________________________________________________
________________________________________________________________
6. List 3 materials that make good conductors?
a. ___________________________________
b.___________________________________
c.___________________________________
7. What is a semi-conductor?
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
8. Briefly explain how a semi-conductor works?
________________________________________________________________
KEY
1. What are electrical conductors?
Answer: Electrical conductors are materials that allow electricity to flow
from one point to another.
2. List the four materials that are good conductors
a. Copper
b. Iron
c. Aluminum
d. Zinc
3. What makes a good conductor, a good conductor?
Answer: Electrical conductors are materials made of atoms that have at
least one free electron.
4. What is an electrical insulator?
Answer: Insulators are materials that DO NOT allow electricity to flow from
one point to another.
5. Why is a good insulator a good insulator?
Answer: Good insulators are materials that Do Not have any free electrons.
6. List 3 materials that make good conductors?
a. Glass
b. Rubber
c. Plastic
7. What is a semi-conductor?
Answer: A semi-conductor is an electrical device made from two types (ptype positive and n-type negative), modified silicon. The combined materials
only allow current to flow in one direction.
8. Briefly explain how a semi-conductor works?
Answer: When silicon has been doped with a material that has 5 electrons, it
causes the act as a good conductor with these free electrons. And is then
mated with silicon that has been doped with a material that has only 3
electrons thereby creating a space for an electron to go (or what is called a
hole). When the proper polarity and sufficient electrical charge is applied,
the extra electrons will flow from the n-type material to the p-type material,
there by allowing current to flow. If polarity of the charge is reversed, no
current flows.
Day 2
1. Students will reform their internet groups.
2. Pass out the Electronic project kits.
3. Have students complete the kit inventory identifying all parts of the kit.
4. Demonstrate the proper use of the solder-less circuit board.
5. Once students have completed their circuit, have them demonstrate the circuit to
you. When this is completed have students select another circuit that utilizes a
diode, build, and demonstrate the circuit.
Extension
Students may build additional circuits that utilize diodes.
Evaluation/Assessment
Students will write three detailed paragraphs, one for each topic, about conductors,
insulators, and semiconductors.
Resources
http://www.howstuffworks.com
http://www.google.com
http://www.ask.com
http://www.altavista.com
http://www.abra-electronics.com/catalog/kits/eki_1101.html