"Look at the battery. What would have the positive charge and what would have the negative charge?" asked Persell Middle School teacher Julie Alfa to her 7/8 15:1 science class, as she reviewed positive and negative charges.
"If I put one wire from the holiday lights on the positive charge and one wire on the negative charge, and it lights up, is that an open or closed circuit?"
"Closed," said a student.
Persell Middle School student Kaylee Fredrick tests a paper clip to see whether it is a conductor or an insulator as part of an electricity experiment in Julie Alfa’s class.
"That's right. So, now we are going to do experiments with the battery to make predictions on whether something is a conductor or an insulator. What is the difference between a conductor and an insulator? A conductor allows the electrical current to flow through, and an insulator does not, right? Let's try to experiments to determine which of these items are conductors and which are insulators."
Alfa's students built a simple circuit with a battery, light bulb and a wire with two ends exposed. Students touched one end of the wire to the positive on the battery, they touched the free end of the wire to the object they were testing such as rubber bands, pennies, paper clips, glass microscope slides, key, nickel and brass paper fasteners and touched that object to the negative.
Before touching the items to the battery, students made written predictions on whether they thought they would be a conductor or insulator. Once they tested the items, they wrote their results. Then using "Step Up to Writing" as a guide, students wrote out a summary explaining their findings. Finally, each group presented their findings to the class with a whole group discussion.
"My students receive the same science curriculum that general education students receive, along with and including, visual/audio strategies, graphic organizers, video clips, hands-on activities," said Alfa. "Being a smaller class size, the students get more one-on-one time with each other and with me. I am able to introduce and model a concept. The pace is consistent with the general education classroom, but I allow for more time in questions, intervention and discussions. The science experiments allow the students a hands-on experience. It brings the notes and lectures to life. It also helps to build a confidence in some of the students."
Alfa's students began with background knowledge of potential and kinetic energy and discussed the different transformations of energy such as chemical to mechanical and examples of each form of energy. Students were introduced to the difference between positive and negative charges using PowerPoint to take brief notes. They talked about conductors, insulators, electrical currents and the moving of electric charge. Students also made observations to explain the electric charge on various objects (tape, balloon, wall). Students were able to explain the differences between positive and negative charges, define attraction and repel and give two examples of a conductor and insulator.