Science Focus Lesson SC.5.P.10.4 Transformation of Electrical Energy Elementary Science Science Focus Lesson SC.5.P.10.4 Transformation of Electrical Energy Benchmark Clarifications Students will explain that electrical energy can be transformed into heat, light, and/or sound energy, as well as the energy of motion. Students will explain that energy from the Sun can be used to heat objects, and that when sunlight is not present, heat may be lost. Students will identify the flow of heat between hot and cold objects and/or that heat may cause objects to change temperature. Students will identify common materials that conduct heat well or poorly. Students will explain that an electrically charged object can attract an uncharged object and/or either attract or repel another charged object without any contact between the objects. Students will determine that the flow of electricity requires a closed circuit. Students will identify and/or classify materials that conduct electricity and materials that do not. Content Limits Items will not assess parallel and series circuits. Items assessing electricity will not refer to electrons or the movement of electrons in producing electrical charge. Items that refer to positive and negative charges in attraction and repulsion properties must be in the context of static electricity. Items will not use more than two energy conversions. Stimulus Attribute Scenarios are limited to abiotic systems. Scenarios referring to energy from the Sun will not use the term radiant. Polk County Public Schools

SC.5.P.10.4 Benchmark: Investigate and explain that electrical energy can be transformed into heat, light, and sound energy, as well as the energy of motion. Essential Question: How can electrical energy be transformed into other forms of energy? Vocabulary: electrical energy transform conductor closed circuit attract repel insulator

transformation of electrical energy Electricity is a form of energy that is produced when electrons move from one place to another place. Electrical Energy can be transformed or changed into heat, light, and sound energy. Heat Sound Light

Electrically Charged Objects Attract means to pull on Repel means to push against + + _ _ Like charges repel each other. + _ Unlike charges attract each other.

Electrically charged objects An electrically charged object can attract an uncharged object and/or either attract or repel another charged object without any contact between the objects. Attraction Attraction Discuss with class: *You can rub a balloon on your hair. This removes some of the electrons from your hair and gives the balloon a slight negative charge. Now put the balloon against a wall. It will stick (if the weather is dry) since the negative charges in the balloon will re-orient the atoms of the wall, and a weak electrical force will hold the balloon in place on the wall. Opposite charges attract. *Charge a plastic comb with static electricity from your hair and use it to bend a stream of water. Again, opposites attract. *Two like-charged balloons hang from a common point from the ceiling. The repulsion effects cause them to hang at an angle from their usual vertical alignment. A plastic tube is charged by rubbing with synthetic fur. The plastic tube is inserted into the space between the balloons, causing even further repulsion. Items that refer to positive and negative charges in attraction and repulsion properties must be in the context of static electricity. Repulsion/Repel

Summarize Partner A: Tell your shoulder partner what 3 ways electrical energy can be transformed and give an example of each. Partner B: Tell your shoulder partner the difference between attract and repel and then tell what happens to like charges and what happens to unlike charges. Partner A should say: Electrical energy can be transformed into heat, light, and sound. Examples: stove, light bulb, telephone Partner B should say: Attract means to pull on and repel means to push against. Like charges will repel and unlike charges will attract.

Electric circuits Electric current flows through a path called a circuit. A circuit is like a big loop. In order for the current to flow through the loop, the path must have no breaks; in other words, it must be closed. A closed circuit has no breaks in it. An open circuit has a break. Items will not assess parallel and series circuits. Items assessing electricity will not refer to electrons or the movement of electrons in producing electrical charge. Closed circuit – Light bulb is on Open circuit – Light bulb is off

Conductors and insulators Anything that allows heat/thermal energy or electricity to move through it easily is a conductor. Anything that slows the movement of heat/thermal energy or electricity is an insulator. Take a look at the picture: The cookie sheet is a conductor. Metals are good conductors of heat/thermal energy and electricity. The oven mitt the mom is wearing is an insulator. Thick fabrics, plastics, and rubber are not good conductors of heat/thermal energy and electricity.

Flow of heat Heat is the transfer of thermal energy between objects of different temperatures. Heat travels from a warmer object to a cooler object. The heat will continue to flow until the temperature of the two objects has equalized, or reached the same temperature. For example, suppose you place an ice cube in a glass of water. Because the water is warmer than the ice, heat flows from the water to the ice until the two reach the same temperature. Heat does not flow from the ice to the water.

Energy from the sun can be used to heat objects. Solar energy mostly passes through the atmosphere and this heat is absorbed by all objects, such as humans, trees, flowers, roads, etc. These objects will then warm up. Dark objects, such as asphalt roads, will absorb and warm faster than light colored objects. When sunlight is not present, heat may be lost.

Summary With your shoulder partner, have a discussion about the following: Discuss the difference between open and closed circuits. Discuss conductors and insulators and give examples Discuss what you have learned about the flow of heat After allowing partners to discuss, go back to the slides and review/check answers. Open/Closed Circuits – slide 7 Conductors/Insulators – slide 8 Flow of heat – slide 9

Guided Practice Work with your shoulder partner to answer each question Benny’s family bought a new electric stove. The stovetop had several large circles on it. When Benny’s father turned on the stove, the circles glowed with a red color. What can you infer about these circles? A. The circles gave off both heat and light. B. The circles gave off only light to show where to place the pans. C. The circles gave off light but not heat. D. The circles gave off light to help the cook see the stove.

“A” is the correct answer! The circles gave off both heat and light.

Guided Practice 2. It was a hot, sunny day. Marsha’s family was at the beach. Marsha took off her sandals and headed for the water. The sand was so hot, she had to run so her feet would not burn. Which of the following best explains why the sand was so hot? A. People running in the sand made the sand hot. B. Heat and light from the Sun made the sand hot. C. Wind blowing over the sand made the sand hot. D. The temperature that day made the sand hot.

“B” is the correct answer! Heat and light from the Sun made the sand hot.

Guided Practice 3. Alex turned on the light in his room so he could do his homework. What type of energy transformation is taking place in Alex’s room? A. electrical to light B. light to mechanical C. mechanical to heat D. heat to electrical

“A” is the correct answer! Electrical to Light

Summary With your shoulder partner, find some sources of electrical energy in your classroom. Name the sources you find and what form of energy it creates. If time, share with the class.

Check Your Understanding Record your answers. Check them at the end. The electric meter at Karen’s house measures the amount of electricity her family uses each month. Last month, her family installed a solar water heater. They no longer use electricity to heat their water. Which of the following can Karen’s family predict? A. Their water bill will go up. B. Their electric bill will go up. C. Their electric bill will go down. D. Their water bill will go down.

Check Your Understanding 2. Which picture shows a closed circuit? A. B.

Check Your Understanding 3. Which of the following items would be the BEST conductor of heat? A. A plastic spoon B. An oven mitt C. A wooden board D. A metal pan

Check Your Understanding 4. If you added ice cubes to a glass of water, which of the following would happen? A. The heat from the glass would flow to the ice. B. The heat from the ice would flow to the water. C. The heat from the air outside the glass would flow to the water. D. The heat from the water would flow to the ice.

Check Your Answers C A D

Summary Write a summary paragraph explaining your understanding of one of the following: *How electricity transforms into other forms of energy *The difference between conductors and insulators *The flow of heat *The difference between open and closed circuits