Between March 13 and April 24, the Science room has turned into a laboratory for the study of electricity, magnetism, and electronics. We began by learning what electricity is — moving electrons.
Static Electricity — We spent a week playing with static electricity, using friction to transfer electrons — and thus charge — from our hair to balloons. Then we tested our charged balloons to see what we could pick up — wool, cotton, and even particles of yeast that pinged up from a plate to our balloons like upside down rain.
Current Electricity and Circuits — Next, we began learning about current electricity — electricity that flows through wires. Students in grades 1 – 5 made Circuit Bugs — lightening bugs made from colorful cardboard, clothespins, and holiday lights. The bugs light up when a circuit is completed with a AA battery. Middle schoolers began working with our new FOSS electronics kits — Full Option Science System — which include springboards for creating circuits, a variety of electronic components, and digital multimeters for testing volts, current and resistance. Middle Schoolers learned how to make and recognize simple, parallel, series and short circuits. They learned what is inside lights — filaments that act as resistors — and why they glow.
Batteries — changing chemical energy to electric energy. All students made batteries using the pattern of Alessandro Volta, the inventor of the battery. They created Volta Piles using pennies, dimes and blotter paper soaked in salt water. They learned that all batteries must have two different metals and an electrolyte, a conductive solution. They tested their volta pile batteries with the digital multimeters and found that they were indeed registering voltage — in other words, experiencing a drop in voltage from one side of the battery to the other. This told us that electrons were moving from one pole of the battery to the other. Next, students made batteries out of lemons and potatoes by inserting a penny into one end of the veggie or fruit, and a galvanized screw — coated with zinc — in the other end. When the two electrodes were tested with the voltmeter, both the potato and the lemon batteries registered close to a volt of electricity. In each case the juice inside — citric acid in the lemon, and potassium sulfate inside the potato — acted as an electrolyte.
Using FOSS kits for Exploring Resistance and Voltage
AFter making batteries and seeing how chemical energy can be converted to electric energy, student continued to explore circuits. Middle schoolers tested resistors in circuits and discovered the relationships between resistance and the brightness of lamps in a series circuit. Some students were able to test potentiometers — variable resistors — and learn their uses in changing the brightness of a lamp, the volume of sound, or the speed of wheels in motion. Next, student measured the voltage across different lamps in a series circuit and learned that voltage drops evenly across a circuit, so that when components are added, the voltage drops evenly across each.
Student of all ages explored magnets — learning what they are, what they do, what they are attracted to, and what a magnetic field can go through. Then students in grades 4 – 8 created electromagnets by winding a wire around an iron nail and putting the ends of the wires on a battery. They found that the more times the wire is wound around the nail, the stronger the magnetism, and the more staples the magnet would pick up.
Middle School students then observed and made (8th graders) electromagnetic motors by creating a coil of copper wire with pivoting ends in an armature of a paper clip. When a battery was hooked up to the paper clips and the motor was held next to a strong magnet, the coil of copper rotated by itself.
This lesson was then extended to make an electomagnetic generator. Insulated wire was coiled around the mouths of two jars and then joined together in an extra long circuit. In one jar a compass was secured with clay, with the north needle pointing in the same direction as the wires. In the second jar, three feet away, a chain of six thick disk magnets was moved in and out of the jar. As the magnets moved, at the other end of the table, the compass needle swung back and forth. This showed that current — which produces a magnetic field — was pushing through the wires.
In addition to labs and class work, two visitors helped us learn how electricity is generated:
Commander Walt Taylor, father of two students, shared his work in Nuclear Energy aboard a nuclear air craft carrier.
Paul Cleary, father of two students, shared his work bringing solar energy to low income families.
Thank you to both these amazing fathers and scientists!!