This chart gives information about the four coal types. Under each coal type, there is a list of characteristics in the following categories:
Anthracite is the highest rank of coal and the oldest coal.
Lignite is the lowest rank of coal and the youngest coal.
* BTUs (British Thermal Units) -- the greater the number of BTUs, the more heat per ton the coal gives off and the more energy it produces.
Problem:
What are some physical properties of coal?
Part 1. Observing Properties of Coal
Gather these materials:
Hand lens
Paper towels or sheets of newspaper
Small nail
Safety glasses
Follow this procedure:
1. Place paper towels or newspaper on your desk or table.
2. Spread several samples of coal onto the paper.
3. Examine your coal samples and observe as many properties as you can. You may use the hand lens and nail during your examination.
4. Record your observations on a sheet of paper.
Part 2. Making Coal Flowers
Gather these materials:
Shallow glass, aluminum, or plastic bowl
Small pieces of coal
White glue
Twigs or toothpicks
Salt
Laundry bluing
Water
Ammonia
Food coloring
Activity:
1. In a shallow bowl place several small lumps of coal.
2. Interlace twigs and/or toothpicks with coal. You may need to use glue to hold the twigs and/or toothpicks to the coal. Allow the glue to dry overnight before continuing.
3. In a separate bowl mix: 2 T salt, 2 T laundry bluing, 2 T water, and 1 tsp ammonia.
4. Pour the mixture over the coal mound.
5. Sprinkle dots of food coloring around the mound.
6. Crystals will begin to form within several hours.
Teacher's Notes
Objective:
Students will investigate properties of coal samples and record at least three physical characteristics.
Materials:
The materials are listed on the student sheet. Small finishing nails are suitable for students to probe and pry apart the coal samples. Obtain coal samples from a nearby utility company. The students need only small pieces of coal for this activity.
Teaching Strategies:
1. Exploration phase -- allow students up to one class period to examine and record observations, properties, etc., of the coal samples.
2. Share observations in whole group or small groups.
3. The coal flowers can be used as a concluding activity done in small groups. You might wish to mix up all of the ingredients ahead of time in one larger batch. Just keep the proportions similar to the recipe given to students.
4. The toothpicks and glue are used to stabilize the pieces of coal.
PLEASE NOTE: The humidity in the room will affect the amount of time needed for crystal formation. Also, the amounts listed for the ingredients are not mandatory, however, you must keep the ratio the same. Try to leave the bowls stationary while the crystals grow.
Activity Results:
Crystals will begin forming as the areas dry. The longer they grow, the larger the area they cover will be. The food coloring will spread as the crystals grow. These may be kept for 2-3 weeks. Crystal formation will be more successful if left undisturbed.
Extended Activities:
1. Students may make drawings and/or write descriptions of their crystal gardens as they grow.
2. If students have had experience with studying properties of minerals, they could do hardness testing and record other properties of the coal samples.
Problem:
How can you make a model of a turbine?
Gather these materials:
1 drinking straw
8 1/2" paper square
String (30 and 20 cm pieces)
Tape, rulers, scissors, paper punch
Paper clips
Follow this procedure:
1. Draw a line between two opposite corners of a piece of paper. Then draw another line between the two other corners.
2. Cut from each corner halfway to the center of the paper. See Diagram 1.
3. Punch holes in every other corner and center as in Diagram 2. Put straw through center hole. Bring corners to center, placing holes over straw as in Diagram 3.
4. Tape a 20 cm long piece of thread to the straw behind the pinwheel. Tie the bottom of the string to a paperclip.
5. Insert a string approximately 30 cm long through the length of the straw.
6. Hold both ends of the string and place the pinwheel in front of a moving air source. See Diagram 4.
Click here to get the diagram
on pinwheel construction
7. Use the pinwheel to raise the paper clip. Find out if your pinwheel can lift ten or more paperclips.
8. Where was the energy source that lifted the paper clips?
Teacher's Notes
Objectives:
1. Students make a pinwheel to serve as a model turbine.
2. Students demonstrate how wind can be used to do work.
Science Background:
A pinwheel is a simple turbine. A moving fluid, such as air, steam, or water, can turn a turbine and create useful mechanical energy. This energy can be used to lift things. It can make electricity by turning the magnets in generators.
Teaching Suggestions:
1. Use student sheets and have students demonstrate technical reading skills.
2. Model the creation of the pinwheel first and have students "copy" you.
3. Combine the reading of student sheets with teacher modeling.
Extended Activities:
1. Use different wind sources and test the strength of them by checking the number of clips they can pull.
Example: Hair dryer (On cool), fan, outdoors.
2. Vary the size of pinwheels to see how size affects the lifting ability.
3. Build several pinwheels of different sizes. Place two, three, or more on the same straw. Repeat the original activity.
Problem:
How does water pressure change as water depth changes?
Materials:
1 paper or plastic milk carton
1 pencil or nail
1 shallow baking pan or dishpan
masking tape
water
Follow this Procedure:
1. Use the pencil or nail to make three equal-sized holes in one side of the milk carton. Make the bottom hole 8 cm from the bottom of the carton. Make the second hole 4 cm above the first hole. The third hole should be 4 cm above the second hole.
2. Cover the holes with a single strip of masking tape, top to bottom.
3. Fill the milk carton to the top with water.
4. Place the milk carton at one end of the baking pan. Make sure the holes are facing the center of the pan.
Predict:
Make a drawing showing the paths you think the water will take coming out of the holes.
5. Quickly pull the tape off the holes. Observe how the water flows out of the holes. Record your observations. Draw a sketch to show the results of this activity.
Think It Over:
1. How did your prediction compare to the actual results?
2. Write your answer to the opening problem question.
3. Take the role of an engineer who is responsible for planning a hydroelectric plant by a dam. You must decide whether to place the plant near the top of the dam or near the bottom. Explain where you would put the hydroelectric plant and why.
4. Why are dams thicker at the bottom than the top?
Teacher's Notes
Objectives:
The student will demonstrate an understanding that pressure of water increases with depth.
Science Background:
Coal, uranium, and the energy from moving or falling water are energy sources used to make electricity. Electricity is produced in a machine called a generator. This machine changes mechanical energy (from steam, water, etc.) to electrical energy. The mechanical energy sources turn turbines which then spin large loops of wire through a magnetic field. When the wire turns in the magnetic field, electricity flows in the wire.
Materials:
See student activity sheet for materials listing.
Please note:
1. Make sure milk cartons are quart or half-gallon size with the top cut off so student's hand can fit in the inside of the carton.
2. Emphasize the first hole is eight centimeters from the bottom.
3. Make sure holes are uniform and remain unobstructed during activity (i.e. -- punch hole from the inside ). Holes can be started with a thumbtack.
4. As an option, you can use 2 liter pop bottles, or 1/2 gallon milk cartons with the tops cut off.
Teaching Suggestions:
1. Read directions on student sheet first, and have students make a prediction about what will occur.
2. Have students do student activity and answer questions on student sheet.
3. Share results in class discussion.
Extended Activities:
1. Have students add an additional hole four cm. up from bottom and repeat activity. Share results.
2. Then use the four hole carton and hold the carton above the pan and see if results change. Discuss findings.
3. Change distance or size of holes on another side of the carton and repeat activity.
Research Ideas:
Research hydroelectric dams. Topics could relate to construction of amous dams or how dams change the environment. The High Aswan dam in Egypt is an excellent example of how a dam can affect the environment.
Answers to Student Questions:
1. Answers will vary depending on student predictions.
2. As the water depth increases, the water pressure increases.
3. The plant would be better placed near the bottom of the dam. The water pressure would be greater near the bottom because of the greater water depth.
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