Teach conductors and insulators by testing everyday objects. First, build an open circuit. Second, select a variety of everyday objects to test. Then let your students get their hands on science!
Ms. Sneed Ponders How to Teach Conductors and Insulators
Our favorite fourth grade teacher, Ms. Sneed, and her teaching partner, Mr. Frank, were planning their electricity unit. “We’ve already worked with batteries and bulbs. And our kids can build simple circuits. Next, we’ll teach about conductors and insulators,” Ms. Sneed said.
“Look at this,” said Mr. Frank. “Our textbook teaches this concept with a reading passage.”
“Yuck,” replied Ms. Sneed. “Let’s do a hands-on activity instead.”
“And as the standards say, kids should collect empirical evidence. But how will we do it?”
“When I was in school, we tested everyday objects. We could build some testers. Then our kids can try it out.”
“Yeah, but how will we do that?” asked Ms. Sneed.
Mr. Frank hurried over to the science cabinet an opened the door. After rummaging around, he pulled out some electricity materials.
While Ms. Sneed watched, he put two batteries in a battery holder. Next, he screwed a 1.5-volt bulb into a bulb holder. Finally, he attached three wires. “See how these two wires are not connected?” he asked.
His colleague nodded. “Well, kids just place both free ends on an object.” He picked up a paper clip and tried it. Ms. Sneed’s eyes opened wide as the bulb lit. “See? When kids test a conductor, the bulb lights.”
Next he tried an eraser. Nothing happened. “But when they test an insulator, the bulb doesn’t light.”
Christmas Tree Light Testers
“Hey,” said Ms. Sneed, “I think I saw something on Pinterest that showed a teacher using Christmas tree lights for this.”
“That would add an element of fun,” responded Mr. Frank. They returned to the computer and searched Pinterest. “Here it is! We’d just cut apart a set of lights and strip the wires. Then we’d just attach one end to the battery holder and add one more wire.”
“Cool!” A smile spread across Ms. Sneed’s face. “But wait, would our 1.2-volt batteries light that bulb?”
After a little searching on the Internet, they found that Christmas tree bulbs were generally 3 volts. Therefore, two of their batteries would do the trick.
Ms. Sneed’s Students Test Electrical Conductors and Insulators
That weekend, Ms. Sneed purchased the supplies. On Monday morning, the two teachers finished setting up. For each group, they placed 20 objects in a baggie.
“We’ve given each group plenty of metal and non-metal items,” said Mr. Frank. “Furthermore, we’ve included organic and non-organic materials. They should be able to make generalizations easily.”
The Class Tests Conductors and Insulators
That morning, after Ms. Sneed’s class filed in, she called them to order. “Okay, everyone, let’s get seated. We’re doing a science lab.”
“Yay!” her class cried, and they hurried to their seats.
“Today you’ll be testing different objects to see if they conduct electricity.” She held up a baggie so they could see. “First, you’ll build a tester using a section of Christmas tree lights, two batteries, and a wire. Let me show you how to put it together.”
After explaining, Ms. Sneed handed out their lab sheets. “Each group member will list conductors in the left-hand column and insulators in the right-hand column. When you’re finished, you’ll make a generalization on the bottom of the page. Feel free to test objects around the room that are not in the baggie as well.”
As she distributed the papers, Ms. Sneed continued. “We’ll use our usual science lab groups. Number 1s, please get a baggie of objects. 2s, grab a Christmas light. 3s, get two batteries and a battery holder. And 4s, take one extra wire for your group.”
Soon the kids worked busily on constructing their testers. As they tried various objects, Ms. Sneed heard comments like, “Hey! The bulb lights even when I connect the wires far away from one another on this metal paper punch.”
As Ms. Sneed circulated, she noticed that they had no trouble with the generalization. Everyone saw that metals conducted and non-metals insulated. She chuckled as she watched one group try the metal leg of a table. “What? The electricity travels all the way through that big table leg?!” one girl cried out.
Ms. Sneed Tackles the In-Between: Resistors
The next day, the teacher was ready to tackle resistors. “All materials are either conductors or insulators, right?” she asked her class. They nodded in agreement.
“What about the filament in the light bulb?” she asked.
“It must be a conductor,” offered a boy in the back corner. Otherwise, the electrical current wouldn’t travel through the circuit.”
“True,” said Ms. Sneed, “but I’d like to categorize it in a different way. The filament is a resistor. Do you notice how it glows when electrons flow through it? That’s because the filament restricts the amount of electricity.”
As she looked out on her class, Ms. Sneed noticed that they had fallen silent. Their faces told her that they were thinking about what she had said – but that they hadn’t totally accepted it.
“Let’s read a short article about resistors,” she said. Ms. Sneed laid the page on her document projector and turned it on.
After reading the article, Ms. Sneed checked their understanding. “So,” she said, “resistors transfer electrical energy to other forms of energy. What transfer occurs in the light bulb?”
Several students raised their hands. “Emily?” Ms. Sneed said.
“The bulb glows, so it’s letting off light energy.” The teacher nodded. “And the bulb gets warm too. That means thermal energy is released.”
Over the course of her career, Ms. Sneed realized that there were 6 steps to enjoy teaching. In order to survive, she had to organize, plan, and simplify. Then, to thrive, Ms. Sneed needed to learn, engage, and finally – dive in! Follow the Fabulous Teaching Adventures of Ms. Sneed and learn how you can enjoy teaching too.