Electricity #19

Table of Contents for #19 Electricity:

Preparation and Support

A TOPS Model for Effective Science Teaching • Getting Ready • Gathering Materials • Sequencing Task Cards • Gaining a Whole Perspective• Long Range Objectives • Review/Test Questions

Activities and Lesson Notes

CORE CURRICULUM
1. 1. Transferring Electrons
2. 2. Like / Unlike Charges
3. 3. Circuit Puzzles
4. 4. Conductor or Insulator?
5. 5. Redistributing Charge
6. 6. Polarization
7. 7. Dancing Circles
8. 8. Build a Bulb Holder
9. 9. Build a Cell Holder
10. 10. Build a Switch
11. 11. Ohm's Law (1)
12. 12. Ohm's Law (2)
13. 13. In Series
14. 14. In Parallel
15. 15. Series or Parallel?
16. 16. Double-Throw Switch
17. 17. Two-Way Switches
18. 18. Switching Maze
19. 19. Build a Galvanometer
20. 20. Test Your Galvanometer
21. 21. Which Path?
22. 22. Variable Resistor
23. 23. Adding Resistances
24. 24. Tiny Fuses
25. 25. Electroscope (1)
26. 26. Electroscope (2)

ENRICHMENT CURRICULUM
27. 27. Electrolysis (1)
28. 28. Electrolysis (2)
29. 29. Electrolysis (3)
30. 30. Build a Wet Cell
31. 31. Build a Storage Cell
32. 32. Charge a Capacitor
33. 33. Ammeter (1)
34. 34. Ammeter (2)
35. 35. Generators and Motors
36. 36. Internal Resistance

Supplementary Pages

lettered millimeter scales • graph paper

 

Complete Master List for #19 Electricity:

Key: (1st/2nd/3rd) denote needed quantities: (1st) enough for 1 student doing all activities; (2nd) enough for 30 students working in self-paced pairs; (3rd) enough for 30 students working in pairs on the same lesson. Five triple starred items below may be purchased in #SK19: Advanced Electricity Starter Kit. Single starred* items may also be purchased below.

1. * 1/1/1: spool thread
2. 2/30/30: squares of 10x10 cm silk cloth
3. * 1/5/5: rolls masking tape
4. 1/15/15: pairs of scissors
5. 2/30/30: styrofoam cups (blocks of polystyrene)
6. * 3/30/30: size-D batteries
7. * 10/100/100: meters bare copper wire, 24 gauge or thinner
8. 1/6/6: pliers with wire cutter
9. 10/120/130: pennies
10. * 2/30/30: traditional flashlight bulbs


11. * 2/30/30: straight plastic straws
12. * 10/200/200: medium or heavy duty rubber bands
13. * 1/1/1: box steel straight pins
14. 1/5/15: tin cans
15. *** 1/15/15: galvanized nails, about 2 1/2 inches
16. * 1/2/2: rolls aluminum foil
17. 1/3/6: paper punch tools
18. * 5/120/120: clothespins
19. * 1/4/4: boxes paper clips
20. 1/15/15: metric rulers


21. 1/15/15: plastic produce bags
22. 1/4/8: meter sticks
23. * 3/60/60: meters (or more) insulated wrapping wire
24. * 2/30/30: baby food jars
25. * 1/15/15: ceramic magnets
26. * 1/1/1: box steel wool, fine-grade, unsoaped
27. 2/30/30: index cards
28. 1/1/1: box: source of corrugated cardboard
29. ***0.1/2/2: liters 5% hydrochloric acid
30. 1/15/15: 100 mL beakers (or baby food jars)


31. * 1/10/15: small test tubes
32. 1/1/1: box baking soda
33. 1/5/15: books of matches
34. 2/30/30: paper towels
35. 1/5/15: plates or petri dishes (optional)
36. 1/1/1: bottle 3% hydrogen peroxide dispensed in smaller dropping bottles
37. *** 6/30/90: split-shot lead fishing sinkers
38. 1/1/1: box table salt
39. *** 1/5/15: capacitors rated 0.1 farad or greater
40. * 0.1/2/2: cups oil based clay


41. *** 2/10/30: 100 ohm resistors rated at 1/4 or 1/2 watt
42. 1/5/15: commercial galvanometer or ammeter with milli-amp sensitivity, needed in 3 activities
43. 1/1/1: bottle vinegar
44. 1/5/15: washers

Convenient Shopping:

Electricity Supplies

WE SUPPLY five hard-to-locate items: 5% HCl in a dropper bottle, six split-shot lead sinkers, one 2 1/2 inch galvanized nail, one 220 micro-Farad electrolytic capacitor, and two 100 ohm Resistor (1/2 watt). YOU SUPPLY everything else.
#ES19: Electricity Supplies @ $12.50 USD

Aluminum Foil

regular strength, 20 square feet x 12 inches rolls

Buy aluminum foil here as a convenience item, or for less in many grocery stores.

#1450: Aluminum Foil @ $3.00 USD per box

Baby Food Jars - assorted

without lids

Each set includes 4 small, 4 medium and 4 large glass jars.

#1260: Baby Food Jars - assorted @ $4.00 USD per dozen set

Batteries

size-D, alkaline

These are basic workhorse brands, available everywhere.

#1440: Batteries @ $1.90 USD each

Clay - modeling

oil-based, non-drying

Sold by the 100 gram stick, about 1/4 cup, in assorted colors (our choice). One stick serves a whole classroom for TOPS applications.

#1150: Clay - modeling @ $1.50 USD per 100-g stick

Clothespins

wooden, spring-action

These are handy lab items to keep in stock. We use them as bulb holders, tongs, clips, and more.

#1100: Clothespins @ $1.00 USD per 10

Flashlight Bulbs

4.5 volt, with collar

This traditional filament bulb shines reliably bright (won't blow out) with 3 size-D batteries, yet still glows visibly with just 1 battery. Used in #19 Electricity, #32 Electricity, and #91 Global TOPS.

Tips on shopping elsewhere: Select bulbs with protruding metal 'collars' to facilitate secure integration into clothespin bulb-holders. Use just one bulb brand and resistance rating so all bulbs shine with equal brightness when powered by equal voltage.

#1270: Flashlight Bulbs @ $2.30 USD each

Magnet - ceramic

rectangle, 3/16 inch thick

Your basic refrigerator magnet, about the width and length of a large postage stamp, with N and S poles on each face and a hole in the middle. A useful and popular science supply used in may TOPS titles. Purchase at least 2 per student.

#1050: Magnet - ceramic @ $0.40 USD each

Paper Clips

size #1, steel, box of 100

Paper clips have 1001 uses in TOPS experiments, and science in general. Feel free to use paper clips you already have, but be aware that different brands come in different sizes and weights. In experiments where uniformity is important, don't mix brands.

#1020: Paper Clips @ $1.40 USD per box

Rubber Bands - assorted

10 grams each of thin, medium and thick

You get 30 grams of soft, strong, durable rubber bands: thin #16 (about 50), medium #32 (about 20), and heavy-duty #64 (about 10). These sizes are specifically selected to work in most TOPS experiments.

#1140: Rubber Bands - assorted @ $1.30 USD per bag

Steel Wool

fine grade, unsoaped

A handy lab supply, for studying electricity. Each pad is about the size of a classic Shredded Wheat biscuit. Used in #11 Oxidation and #32 Electricity.

#1210: Steel Wool @ $1.00 USD per pad

Straight Pins

steel, one and 1/16 inch long

Used in many TOPS experiments. Sometimes required for their magnetic properties. Don't purchase aluminum straight pins by mistake.

#1030: Straight Pins @ $3.00 USD per pkg of 150

Straws - straight

plastic, thin

Any length straw, between 0.20 and 0.25 inches in diameter is suitable. Grocery stores generally carry straws with flexible "elbows." You can use those if you cut off the bendable section before using.

#1070: Straws - straight @ $1.40 USD per bundle of 50

Tape - masking

3/4 inch x 60 yd roll

A handy science supply used in most TOPS modules.

#1010: Tape - masking @ $1.20 USD roll

Test Tube - small disposable

6 mL capacity, 12 mm OD, 3 inch (75 mm) length

A lighter weight rimless Pyrex test tube made with thinner glass.

#1175: Test Tube - small disposable @ $0.30 USD each

Test Tube - small reusable

9 mL capacity with 13 mm OD and 4 inch (100 mm) length

A tough Pyrex test tube made with rim and thicker glass. Has a white spot for labeling.

#1172: Test Tube - small reusable @ $1.10 USD each

Thread

light duty, 25 yd spool

Just plain old thread. Used in many TOPS titles, especially in Pendulums #34.

#1130: Thread @ $0.25 USD per spool

Wire - 24 gauge copper

bare wire

This science lab staple is used in #19 Electricity, #20 Magnetism and #33 Magnetism.

#1302: Wire - 24 gauge copper @ $1.60 USD per 3 meters

Wire - wrapping

100 feet, plastic insulated

Also called magnet wire or bell wire. This science-lab staple is used in #19 Electricity, #20 Magnetism, #33 Magnetism, and #91 Global TOPS.

Wrapping wire may be recycled from old motors or transformers. If insulated with paint rather than plastic tubing, end leads will need to be sandpapered clean, not stripped with pliers.

#1301: Wire - wrapping @ $7.90 USD per roll

Teaching Tips for #19 Electricity:

We encourage improvisation - it's one of the main goals of our hands-on approach! You and your students might invent a simpler, sturdier or more accurate system; might ask a better question; might design a better extension. Hooray for ingenuity! When this occurs, we'd love to hear about it and share it with other educators. Please send ideas and photos to tops@canby.com.

Lesson by Lesson Objectives for #19 Electricity:

1. Lesson 1: To understand electrostatic attraction between objects as a transfer of electrons.
2. Lesson 2: To observe electrostatic repulsion and attraction between objects of like and unlike charge. To understand why electrons flow through a wire.
3. Lesson 3: To discover, through trial and error, how to properly wire a circuit. To identify the important contact points on a dry cell and light bulb.
4. Lesson 4: To classify materials as conductors or insulators. To understand how these are used in the design of a light bulb.
5. Lesson 5: To induce a redistribution of charge in a neutral conductor. To charge and discharge by contact.
6. Lesson 6: To observe and explain induced polarization in a stream of water and in solid insulators.
7. Lesson 7: To polarize insulating and conducting circle punches in an electric field. To compare their charging and discharging characteristics.
8. Lesson 8: To construct a bulb holder to use in all circuit-building activities.
9. Lesson 9: To construct a cell holder to use in all circuit-building activities.
10. Lesson 10: To construct a switch to use in all circuit-building activities. To build a simple circuit.
11. Lesson 11: To develop a kinesthetic sense of current, voltage and resistance. To understand how these variables are interrelated by Ohm's law.
12. Lesson 12: To develop a kinesthetic sense of current, voltage and resistance. To practice applying Ohm's law.
13. Lesson 13: To diagram and build circuits in series. To explain current variations in terms of Ohm's law.
14. Lesson 14: To diagram and build a parallel circuit. To understand the advantage of parallel wiring.
15. Lesson 15: To discover that voltages add as cells are connected in series.
16. Lesson 16: To build a double-throw switch that alternates current through two separate bulbs.
17. Lesson 17: To build a set of two-way switches that independently operate a bulb.
18. Lesson 18: To trace the flow of electricity through a complex maze of switches
19. Lesson 19: To construct a sensitive galvanometer. To observe that moving electrons create an associated magnetic field.
20. Lesson 20: To observe that galvanometers are sensitive to the direction that electrons flow through a wire. To use this property to determine the relative strengths of two dry cells.
21. Lesson 21: To observe how current flows through wire in inverse proportion to its resistance, in accordance with Ohm's law.
22. Lesson 22: To control currents in a circuit by operating a variable resistor. To understand that resistance increases as a wire's length increases.
23. Lesson 23: To understand that resistance increases as a wire's diameter decreases. To add resistances in series and in parallel, then observe the combined effect.
24. Lesson 24: To understand how fuses work to protect circuits from shorts and overloads.
25. Lesson 25: To build an electroscope and learn to charge it. To explore various ways to discharge it.
26. Lesson 26: To learn to identify the charge on an electroscope. To charge it by contact and by induction.
27. Lesson 27: To observe how hydrogen ions accept electrons to form hydrogen gas, and chlorine ions release electrons to form chlorine gas.
28. Lesson 28: To separate a test tube of water into oxygen and hydrogen gas.
29. Lesson 29: To study how current separates water into its component gases. To release stored electrical energy by a chemical reaction.
30. Lesson 30: To build a cell that converts chemical energy into electrical energy. To understand this process as the reverse of electrolysis.
31. Lesson 31: To build a working model of a storage cell. To understand why charging and discharging the cell reverses current through the circuit.
32. Lesson 32: To charge and discharge a capacitor. To compare its operation to a storage cell.
33. Lesson 33: To quantitatively correlate the deflection of an improvised galvanometer to changes in current.
34. Lesson 34: To calibrate an ammeter in mill-amps. To use it in measuring current.
35. Lesson 35: To model a generator and electric motor. To understand the distinction between AC and DC.
36. Lesson 36: To graph a cell's current output as a function of its internal resistance. To verify Ohm's law.

National Science Education Standards (NRC 1996) for #19 Electricity:

TEACHING Standards

These 36 task cards promote excellence in science teaching by these NSES criteria:
Teachers of science...
A: ...plan an inquiry-based science program. (p. 30)
B: ...guide and facilitate learning. (p. 32)
C: ...engage in ongoing assessment of their teaching and of student learning. (p. 37)
D: ...design and manage learning environments that provide students with the time, space, and resources needed for learning science. (p. 43)

CONTENT Standards

These 36 task cards contain fundamental content as defined by these NSES guidelines (p. 109).
• Represent a central event or phenomenon in the natural world.
• Represent a central scientific idea and organizing principle.
• Have rich explanatory power.
• Guide fruitful investigations.
• Apply to situations and contexts common to everyday experiences.
• Can be linked to meaningful learning experiences.
• Are developmentally appropriate for students at the grade level specified.

Unifying Concepts and Processes

NSES Framework: Systems, order, and organization • Evidence, models and explanation • Constancy, change, and measurement • Form and function
Core Concepts/Processes: Current (measured in amperes) is proportional to voltage (measured in volts) and inversely proportional to resistance (measured in ohms). • Generators convert mechanical energy into electrical energy. Motors do the reverse.

Science as Inquiry (content standard A)

NSES Framework: Identify questions that can be answered through scientific investigations. • Design and conduct a scientific investigation. • Use appropriate tools and techniques to gather, analyze, and interpret data. • Develop descriptions, explanations, predictions, and models using evidence. • Think critically and logically to connect evidence and explanations. • Communicate scientific procedures and explanations. • Use mathematics in all aspects of scientific inquiry.
Core Inquiries: Configure series and parallel circuits. Predict the flow of current using Ohm's law.

Physical Science (content standard B)

NSES Framework:Electricity • Properties and changes of properties in matter • Motions and forces • Conservation of energy • Interactions of energy and matter
Core Content:Static electricity • Circuits • Current • Voltage • Resistance • Ohm's law • Storage cells • Ammeters • Capacitors • Generators • Motors

Science and Technology (content standard E)

NSES Framework: Abilities of technological design • Understanding about science and technology Core Content: Build galvanometers, variable resistors, fuses, electroscopes, wet cells, and storage cells.

History and Nature of Science (content standard G)

NSES Framework: Science as a human endeavor • History of science Core Content: Hans Christian Orsted (1777-1851) discovers electromagnetism.