Posting Seven -- Series and Parallel Circuits

One of the hardest concepts for students in the grade nine applied science course to fully understand is the parallel electrical circuit. I have tried many different approaches to teaching the parallel circuit over the years but it appears that the learners are not yet ready for this concept. This year I took an inquiry-based learning approach and the results were more successful than in the past.

1. Initiate and Plan – ENGAGE

We began our study of electrical circuits with the series circuit. This allowed us to become familiar with the parts of the circuit (load, source, conductors, and switch) and trouble shoot problems that are commonly encountered when connecting the circuit.

Once the class could build a simple series circuit I taught them the symbols used to record their circuits. You can read more about this process in the previous blog entry (posting six). It is also an excellent example of how the conclusion of one inquiry becomes the initial planning stages of the next inquiry.

As an introduction to the parallel circuit, we watched a video wherein both the series and parallel circuits where examined and explained using age appropriate language and examples. Then we watched a simple power point presentation that I created that covered the same ground. Then we took notes, in the form of a t-chart, to compare the two types of circuits. Next, we did a set of questions together, step by step, that covered series and parallel circuits. Finally, for our exit card that day I distributed small recipe cards. The students were instructed to use the appropriate symbols to draw a series circuit on one side of the card and a parallel circuit on the other side of the card. They were allowed to use their note books, text books, confer with each other and check with the teacher during this process (diagnostic or “assessment for learning”).

2. Perform and Record -- EXPLORE

Prior to the next class I went through each of the cards. Using two sets of stickers – big stars and little stars—I assigned groups and which parallel circuit would be built. I used colour coded big stars to determine which students would work together in small groups, students with the same colour big stars would be in the same group. I used smaller stars to determine which parallel circuit I would require them to build –the circuit drawing with the small gold star would be built. In this manner, everyone go two stars—because they are all stars -- yet I got to mix the groups up and control what circuit would be created. The students responded amazing well to this sticker system and seemed quite pleased that I had made at least some of the decisions for them!

It is not uncommon to have some students absent everyday in applied classes at our school. For those students who were missing on the day we made our cards I took a blank card for each of them, wrote the absent student’s name on it and put two star stickers on the blank card – one large one to determine the group the student would be in and one small one, that was any colour except gold!

The next day the cards on which series and parallel circuits had been designed were returned to the students along with the instructions to move into their assigned groups, pick up all the equipment they needed to build the circuit drawing with the gold star on it and go to it!

The students were soon demonstrating their ability to read circuit diagrams, planning what equipment they needed to build their circuits, constructing circuits, using instruments (voltmeters and ammeters), and experimenting to see if they could successfully complete the task.

3. Analyze and Interpret = EXPLAIN

As stated previously, building parallel circuits is very challenging for students in the grade nine applied science class so it was not surprising to me that this task took a lot of time and patience on behalf of the students. While trying to succeed they engaged in constant analyzing, evaluating and reviewing in numerous attempts to get their circuits working. Of the four groups one group finished much sooner than any of the other three. At that stage I dispersed the members of the successful group amongst the other three groups to be their “consultants”.

It was interesting for me to observe many group members using the voltmeters to determine that there was in fact current running through the parallel branches even though the light bulbs were not coming on.

4. Communicate = EXTEND

Now the students took the initiative to test all the light bulbs in their circuits and replace the ones that were not functioning. They even wanted to know the proper way to dispose of the burnt out bulbs!

This weekend I am working on my midterm report cards marks. This class has a mean score of 82%. Now I am worried that my administration will be questioning why my marks are so high! If they do, I shall refer them to this blog!

Here are some videos showing the levels of engagement in the students during this inquiry!

Posting six -- Current Electricity -- The Electrical Circuit

Today my grade nine applied science class performed an open ended lab on electrical circuits. We started by drawing a simple T-chart to list the symbols for the basic parts of a circuit (battery, wire, open and closed switch, light bulb, etc). We talked about how these symbols could be used by electricians anywhere to wire up a building, it didn’t matter what language they spoke the symbols would be the same.

1. Initiate and Plan = ENGAGE

I drew a super simple circuit diagram, using symbols, on the board and told the students to work in small collaborative groups build it.

I did not distribute any materials. I showed the students where all the materials were, in containers, on the side counter and told them to get what they needed. At first the students questioned how they were supposed to know what materials they needed. I simply told them to refer to their t-charts to decide what they should take from the bins. It took them about 20 seconds to figure it out!

The students investigated how to build the circuit and called me over to show me when the light bulb came on.

My second instruction to the students was to “construct at least four more working circuits and use the symbols to draw them”. Questions that were quickly asked, and answered, by the class included:

“How will we know if the circuits work?” “The light bulb will come on.”

“If we include a switch in our circuit should we draws it with the switch open or closed?” “Draw it both ways and then we will have two circuits done already!”

“What if the battery is dead?” “Then the light bulb won’t come on.”

“”How we will know if we blow the bulb?” “We will hear and see it pop.”

Really, the students did not need me. Together they had enough knowledge to perform the task perfectly. So I gave them some “special pink paper” to draw their circuits on and let them go to it.

2. Perform and Record = EXPLORE

The students designed a number of circuits. Interestingly, they were all series circuits. I thought that given enough time some might move onto parallel circuits. They enjoyed constructing the circuits and experimenting with various combinations of electrical equipment.

Safety note: The source of electricity was D cell batteries (1.5 volts, when new) and each group was limited to three of them so there was no danger of electric shock.

3. Analyze and Interpret = EXPLAIN

Although some of the students used the symbols correctly right from the start, to record their circuits, other students insisted on making artistic renditions of their circuits when instructed to draw them. When asked why they didn’t just use the symbols which were so much quicker and easier they replied “but I really like art.”

Others didn’t want to draw anything at all but when they realized how quickly they could sketch the symbols they decided it was easier to comply than to waste time arguing.

A few used the symbols correctly but drew their circuits as a straight line. When it was pointed out to them how the circuit actually went around in a continuous loop they quickly recognized the error of their ways and were pleased that it could quickly be corrected by drawing a wire from the end of the line around to the beginning rather than starting over from scratch.

4. Communicate = EXTEND

Once all the groups had built and drawn four circuits we discussed the problem of how to decide if it was the battery or the light bulb that was defective when a circuit was built correctly but didn’t work. This is when I introduced the voltmeter.

Without further instructions the class rushed to collect all the batteries out of the container and test them using the voltmeters (using instruments). This led to them discovering what to do if the voltmeter needle went in the wrong direction and what scale to choose on the voltmeter. Indeed five dead batteries were removed from the collection. When the students observed that I was asking them to give me the dead batteries and that I was placing them in a clean plastic jar rather than throwing them into the garbage they questioned me about this practise. This lead to some reflecting and explaining regarding the correct disposal of batteries and what would happen if they went to the landfill.

Once we had all decided that all the batteries were functional it was a natural progression to then test all the light bulbs. The next teacher to use our equipment will be very pleased – everything is fully functional and all the trouble shooting has been done for her!

How will I evaluate today’s lab? I collected the pink papers that the students had drawn their circuits on. This has provided me with documentation on their learning process.

Static Electricity – Creating an Electrostatic Series -- Posting five

I have been re-energized by attending a Smarter Science symposium over the weekend so today I facilitated an inquiry-based collaborative learning experience into electrostatic series with my grade nine applied class.

1. 1. Initiate and plan – ENGAGE

I began the class by modeling how a balloon holding static charge can be used to pick up pieces of confetti (the holes collected out of my hole-puncher). We drew on our previous knowledge, from last week’s classes, to determine how the balloon could be charged with static electricity.

I told the students that we were going to do an investigation to determine what material would produce the greatest static charge on the balloon. In the middle of the sun burst diagram we wrote: “What type of material will make the most static electricity?” This was our dependent variable.

We used the sun burst diagram to list all the different things that could observed while doing a lab.

These were:

1. The time spent rubbing

2. The type of rubbing

3. The shape of the balloon

4. The size of the balloon

5. The colour of the balloon

These items were listed on to little post it notes and stuck around the rays of the sun burst diagram.

We moved to page two of the sun burst diagram, to the Initiate and plan page, which has a picture of the brain and says “brainstorming” on in. Here we decided how we would control the variables that we had listed on our post it notes. This could have been done group-by-group but I chose to do it as a large group activity so everyone would be controlling variable in the same manner. Several excellent suggestions were made so we voted to decide which ones to go with. For example, the amount of time spent rubbing could have been 30 seconds, 60 seconds, 90 seconds, etc. All were good choices so I narrowed it down to the first four suggestions and we voted, by a show of hands. Thus, the controls were determined to be:

1. Time rubbing = 1.5 minutes

2. Type of rubbing = circular motion

3. Size of balloon = full capacity

4. Colour = orange (that’s what I had the most of)

5. Shape of balloon = oval

Now we moved all of our post it notes over to the fish bone diagram where they were taped down. I had actually forgotten that we should tape them down at this point but the kids quickly reminded me.

2. Perform and Record = EXPLORE

The students designed an observation table by drawing a simple t-chart. On the left side they wrote “type of material” and on the right side they wrote ‘number of pieces of confetti collected”. Working in pairs they performed the investigation and were incredibly intr4igued by it. It made me realize how much of the sense of wonder grade nine students still have in them.

Some of the comments I heard during the lab were:

“I can hear the static electricity!”

“Listen!”

“You can hear it crackling!”

“Don’t forget to discharge between tests.”

“Make sure you rub in little circles.”

“It’s your turn to time while I rub.”

“Let’s split the amount of confetti pieces we have to count and each count half of them then add our two answers together.”

3. Analyze and Interpret = EXPLAIN

After testing a variety of materials, such as wool, silk, hair, fur and plastic the students were able to analyze their data to determine which materials created the most static and which created the least. At this stage I introduced them to the concept of “Electrostatic Series” with a very simple definition of “ a list of materials from the most static to the least static”.

4. Communicate = EXTEND

Each student created an electrostatic series by listing the materials they tested, in order, from those that created a static charge to those that created the least. They were able to quantify their results because they had counted the number of pieces of confetti that was attracted to the balloon during each test.

Cleaning Up Oil Spills – Major Lab Investigation for Grade 9 Applied Science Ecology Unit -- Week Four

1. Initiate and Plan = ENGAGE
Day One
In a large group the topic of the major oil spill in the Gulf of Mexico was discussed. Most students were aware that there had been an oil spill somewhere at some time but little else was known about it. (Too far away, too abstract, no connection to us.) In order to prod some concern about it I referred to a food chain which contained fish and has humans as the top carnivore. A “thumbs up – thumbs down” was done to survey how many of the students ever eat fish. A majority do.
An overhead photograph was projected onto the screen showing the extent of the oil along the southern US coast during the summer of 2010.. The question was posed: “Would you want to eat a fish that had been in an oil spill? “Eww Gross! No way!” Now they were interested!
Although it is my policy not to assign homework to this class (since they are not going to do it and it only stresses me out) I told them they were talk to their parents or goggle ideas of how an oil spill could be cleaned up. Don’t write anything down, just collect ideas. (Questioning, Interviewing, Searching)

Day Two
Students were asked what ideas they had learned about ways to clean up an oil spill. Not surprisingly only three students had actually pursued the research and of them only one had come up with an idea which was “use ropes of human hair”. Still it was a start.
On the projector we went to “Goggle Images” and Goggled “Cleaning up oil spill”. I chose to use images since these students are reluctant readers who are very capable of extracting information from pictures. (Searching, Observing) One student was our scribe to keep track of the ideas we could find through our research, she was instructed to just jot down one word for each idea – no details. In about 10 minutes our list looked like this:
Hair
Sawdust
Hay
Wax
Diapers
Kitty litter
Cattail fluff
Filtering

Day Three
Instead of modeling how we could possible use any of these items to clean up oil We used “Google Videos” to watch a couple of videos which showed how these various items were used to clean up oil. (Searching, Observing)
2. Perform and Record (EXPLORE)
Still day three!
The class was broken into small groups and each group took the responsibility of testing two of the substances listed above. This allowed some substances to be tested more than once. The students were not given any instructions on what procedure to follow. A counter was set up with what I felt was a reasonable amount of equipment and apparatus and each group had to decide for themselves what to do. The only thing I insisted on was conformation to our lab safety rules, ie. Wear goggles and tie back you hair. Group members were not assigned specific roles. This allowed me to observe who were the natural leaders, followers, and do-nothings.
Group dynamics were quickly established and amazing tests were carried out. (Planning, Designing, Constructing, Experimenting)

3. Analyze and Interpret (EXPLAIN)
Prior to clean up, the students were instructed to walk around the lab and look at what each of the other groups had done. They were provided with post it notes and told to rate the ability of each substance to clean up an oil spill on a scale of I to 10, with 1 being the worst and 10 being so good you would feel comfortable drinking the water that remained. (Gathering Data, Recording, Comparing, Contrasting, Analyzing, Evaluating, Reviewing)














4. Communicate (EXTEND)
The overwhelming consensus amongst the students was that cattail fluff was the best substance to use to clean up an oil spill! (Discussing, Reporting, Reflecting)

DAY FOUR
Back to Initiate and Plan (ENGAGE)
Now it was time for a controlled experiment. We used the Smarter Science starburst diagram to determine what we could measure and control in a repetition of yesterday’s experiment. A large poster of the diagram was put on the board and each student was provided with post it notes and an individual copy of the diagram. The class was asked: “What could we have measured in yesterday’s experiment?” A list of items was quickly brainstormed, each item recorded on a post it note and stuck on the rays of the starburst diagram. The list was:
How much oil was added?
How much water was added?
What size basin was used?
How much stirring was done?
How much of the substance was added?
How long were all the materials in contact?
How much oil was removed?
The students quickly decided that the final question,”How much oil was removed?” was the one variable they could not control and it would be the one they tested for.
Armed with this information we worked in small groups to design a second experiment which would allow us to quantify our results. Each group designed an experiment where all materials were carefully measured. By the end of class they all had a detailed list of materials and apparatus as well as a written procedure ready for the next day! (Questioning, Predicting, Hypothesizing, Planning,
Designing)
DAY FIVE
Back to Perform and Record (EXPLORE), Analyze and Interpret (EXPLORE AND EXPLAIN) and Communicate (EXTEND)
Today was a culmination of a week of an exciting and dynamic investigation. Students rushed to class early. They didn’t want to wait for me to take attendance, they were so eager to get to work!
Each group worked in a safe and efficient manner to create their oil spills and subsequently clean them up with the cattail fluff. It didn’t take long to realize a major source of error with our plans was that we couldn’t measure the amount of oil soaked up by the cattail fluff since it could not be squeezed out of the cattail fluff, as previously predicted. None the less the students declared the experiment a huge success.
They were in the midst of cleaning up when the class clown declared we should set the oil soaked cattail fluff on fire! This idea rippled around the room as quick as a wink. As it was discussed and joked about it was refined.
“We can’t light it on fire in here --- it would burn the school down!”
“Won’t it be too wet to light?”
“Did they try lighting the oil in the Gulf on fire?”
“Wouldn’t burning it make a lot of air pollution?”
“Would it stink?”
“Maybe it would just blow up.”
“But I have asthma....”
My teachable moment had arrived!
With very little prompting, the first group to finish cleaning quickly got on their itouches and learned that in fact 25% of the oil spilled into the Gulf was burnt off! They showed each other pictures of the dark plumes of smoke created by such a fire.
Once order was restored I told the class how proud I was of their work this week. (Was it work?!) We made a plan. The oil soaked cattail fluff was set to dry in the green house. The next time I have a supply teacher, if I get a good note about the class we are going to sneak out the back of the school and attempt to light the fluff on fire! (Please don’t call my principal!)
As a final activity for the week the students were asked to complete an exit ticket. On post it notes they had to write down one question that they were left wondering about oil spills. Some sample questions they wrote are:
I wonder what happened to the fish.
Will it really burn?
How was the real oil spill cleaned up?
What about the birds?
How did it happen?
Another successful week with the grade nines. Science is fun!

Watch the videos below to see how engaged the students are!

The Photo Essay: Week Three

The grade nine applied science students have decided that they like the class because “we never do any work”. Well! Let me tell you about what we did this week and you decide!
Step One: Initiate and Plan (ENGAGE)
Our school, St. Pius X High School in Ottawa, had a solar panel array installed over the summer months as part of our board’s commitment to renewable energy the solar array is used to capture the sun’s heat as a means of heating the hot water used throughout our school. Since we are currently studying the ecology unit, I told the students about this initiative and arranged an onsite field trip for them to observe this process from beginning to end. The students were encouraged to use their digital cameras, cell phones and other electronic devices to take photos of the various stages involved in the creation of our hot water.
Step Two: Perform and Record (EXPLORE)
On the first day of our “field trip” the head custodian took us up onto the school’s roof. This was fairly time consuming since we had to climb up a ladder and, in the interest of safety, only one person could be on the ladder at a time. Once we were all on the roof we observed the solar panels, what they looked like, which way they were oriented, the angle they were set at and the two large pipes attached to them. These two pipes were clearly labeled “glycerol in” and “glycerol out”. After much discussion and many photos we descended the ladder and now class was over. So no work? Any learning?
On the second and third days of our investigation to observe how our school uses the sun’s energy to generate all of our hot water, we followed the path of the glycerol pipeline from where it enters the school building to a small room tucked away at the back of our library. Here we checked the temperature gauges that showed the temperature of the glycerol prior to entering the tanks. Inside the sealed tanks, we were told that the glycerol pipe encircles a central core containing water and the heat is transferred from the glycerol to the water. By comparing the temperature of the glycerol as it left the tanks, to return to the roof, we realized that there was a temperature differential of 21 degrees C. Again we took lots of pictures before proceeding to the schools’ basement where we observed the boiler where the water that was heated by the glycerol is held until it is needed, at which point it is mixed with cold water, if necessary. These students have only been attending this school for less than three weeks so it was thrilling for them to go behind the scenes in the out-of-bounds areas of the school that are the domain of the custodians! Two more days with no work! Boo hoo! For the first time ever there was homework however! The students were told to email or forward the photos they had taken to me.
Prior to the next class I collected all the electronic photos that I could and posted them in my mailbox, which is available for the students to see on our school computers.
Step Three: Analyze and Interpret (EXPLAIN)
Day four we went to the computer lab. For all but two of these grade niners this was their first visit to the computer lab since entering high school. First I had to teach them how to log on to our network and then show them how to retrieve the photos from my mailbox and import them into Microsoft Photo Story. Although none of them had used Photo Story before they actually figured it out before I had time to show them. Any technical questions they had they asked each other and I was just along for the ride. Another day with no work! Yay!
Step Four: Communicate (EXTEND)
Day five we continued creating our photo essays of “How Hot Water is Produced at St. Pius”. About half way through the day one of the new comers to my class asked me to review his understanding of the project with him. He explained the whole system to me starting with the glycerol circulating through the solar panels in the roof and ending with the hot water coming out of the taps. “You mean to say that all the hot water for this whole school is made just from the heat of the sun?!” he clarified. “Yes, yes it is”, I replied. “So it doesn’t cost the school anything to make all the hot water for this whole building? The cafeteria? The washrooms? Everywhere?” his eyes were widening! HIGH FIVES ALL ROUND! They got it! Sadly, another day with no work. I wonder when they will realize they are learning?


To read about one of my senior super stars click on this link:
HYPERLINK "http://www.ottawacatholicschools.ca/announce.php?annon=10349"St. Pius X student’s keen interest in science leads to summer camp - in California!__