TEKS UNWRAPPED. Key Concepts. Fundamental Questions. 6.9C: Energy Transformations. Prior Knowledge/TEKS e. Rice Universa,, - All Rights Rese

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1 6.9C: Energy Transformations Force, Motion, and Energy TEKS UNWRAPPED The student knows that the Law of Conservation of Energy states that energy can neither be created nor destroyed, it just changes form. The student is expected to: Demonstrate energy transformations such as energy in a flashlight battery changes from chemical energy to electrical energy to light (Supporting Standard) Prior Knowledge/TEKS 4.6 A: Differentiate among forms of energy including mechanical, sound, electrical, light, and heat/thermal. 5.6 A: Explore the uses of energy including mechanical, light, thermal, electrical, and sound 5.9 B: Describe how the flow of energy derived from the Sun, used by producers to create their own food, is transferred through a food chain and food web to consumers and decomposers. Key Concepts Energy is neither created nor destroyed; it changes from one form to another. There are many different forms of energy, such as chemical energy (energy stored in bonds between atoms), electrical energy (energy of electric currents), and light energy (energy of electromagnetic waves). Energy transformations occur regularly in our lives, such as when we use a flashlight (chemical to electrical to light energy), light a match (chemical to light energy), or digest food (chemical to thermal). Food chains and food webs are also examples of an energy transformation as radiant energy is transformed to chemical energy in plants, and chemical energy is transformed into mechanical energy (movement) in animals. Fundamental Questions Why are energy transformations important to everyday life? How is chemical energy transformed to electrical energy in a battery? How do we use transformations of electrical energy? 2012 e. Rice Universa,, - All Rights Rese

2 6.9C: Energy Transformations Force, Motion, and Energy TEKS UNWRAPPED Dissecting TEKS Nouns energy chemical energy transformation battery electrical energy light energy bond atom electric current electromagnetic wave mechanical energy radiant energy Dissecting TEKS Verbs Demonstrate 1. To show or explain how something is used or done 2. To prove something by showing examples of it Bloom's Taxonomy: Comprehension Bloom's Revised: Understand Prompts at the UNDERSTAND level include: Interpret, Exemplify, Explain, Demonstrate, Translate, Summarize, Compare, Infer, Classify How will your students UNDERSTAND the concepts in 6.9C TEKS? Examples of prompts for this level of content knowledge include: Explain how energy from the Sun can be transformed to be usable to animals. Give examples for each of the following energy transformations: chemical to electric; mechanical to thermal; electric to thermal. Definition Source: Merriam Webster Dictionary '2012 in Rice Uniwr ity - All Reserved

3 6.9C: Energy Transformations Force, Motion, and Energy TEKS UNWRAPPED Released SAMPLE STAAR ITEM TEKS: 6.9C, Answer (B) Wind Turbine System Blades 2 KR.,tating blades urn rotor in lenerator Generator 1 Wind energy turns blades of wind turbine 3 Energy moves from generat into powt Ines 4 Energy moves f )ugh power 1 nes Energy from power tines. -auses filaments in toaster to glc Power lines ixr roar tr In the diagram above, 3 wind turbine is transforming energy from the wind. Between which two steps n the diagram is mechanical energy being converted into electrical energy? A 1 ancl 2 B 2 and 3 C 3 and 4 D -4 and 5...-' 201 2In Ricci iniversitv - An Rights Reserved Reseed

4 8th Grade Science 6.9C Name Class/Grade Date 1 Expectation: 6.9(C) Which of the following best describes the type of energy transformation that occurs during photosynthesis? A B C D Chemical energy is transformed into magnetic Thermal energy is transformed into light Light energy is transformed into chemical Electrical energy is transformed into mechanical 2 Expectation: 6.9(C) An electric car transforms electrical energy into F mechanical energy and light G sound energy and chemical H nuclear energy and light 3 heat energy and chemical Progress Testing Page 1

5 8th Grade Science 6.9C 3 Expectation: 6.9(C) The diagram below shows a solar cell. sunlight anti-reflective coating \ front contact specially treated semi-conductor material back contact Courtesy of NASA, 2011 At what point is light energy transformed into electrical energy? A 2 B 3 C 1 D Progress Testing Page 2

6 8th Grade Science 6.9C 4 Expectation: 6.9(C) When electric power is carried over long distances through power lines, the electrical energy decreases as the distance increases. This energy decrease occurs because the current encounters resistance in the wires. Which of the following best describes what happens to the missing electrical energy? F G H The energy is transformed into electromagnetic energy and is released as microwaves. The energy is transformed into thermal energy and is released into the atmosphere. The energy is transferred to the current's electrons as the power lines are grounded. 3 The energy is transferred to the air as light energy as it travels along the power line. 5 Expectation: 6.9(C) A wood fire transforms the chemical energy stored in wood into A B C D light mechanical energy electrical nuclear Progress Testing Page 3

7 8th Grade Science 6.9C 6 Expectation: 6.9(C) Coal is the fuel source used to power steam engines. Which statement best describes the energy transfer that takes place in a train powered by a steam engine? F G H Some of the coal's chemical energy is transformed into mechanical energy, and some is released as heat and light. Most of the coal's chemical energy is destroyed as the coal is burned. Most of the coal's electrical energy is captured and used to power the train. 3 All of the coal's electrical energy is lost as heat and light when it is burned. 7 Expectation: 6.9(C) Fireworks transform chemical energy into A mechanical energy and electrical B sound energy and electrical C nuclear energy and sound D heat energy and light 8 Expectation: 6.9(C) A radio is a device that converts energy from one form to another. Which of the following best describes the energy conversion process that takes place in a radio? F G H Sound is created by energy stored in the speakers. Electrical energy is converted into sound energy and heat Some energy is released as sound, and the rest is destroyed. 3 Electrical energy is converted into chemical energy and sound Progress Testing Page 4

8 8th Grade Science 6.9C 9 Expectation: 6.9(C) Which of the following is an example of a transformation of chemical energy into electrical energy? A B C Sunlight providing power to a solar calculator A blowtorch welding two pieces of metal together An oil lamp lighting up a room D A car battery making headlights shine 10 Expectation: 6.9(C) A construction worker swings a hammer and hits a nail. After the hammer hits the nail, mechanical energy is transformed into F G H light electrical heat energy and sound 3 wind energy and nuclear 11 Expectation: 6.9(C) A windmill transforms the mechanical energy of the wind into A chemical B light C electrical D nuclear Progress Testing Page 5

9 8th Grade Science 6.9C 12 Expectation: 6.9(C) A microwave transforms electrical energy into F G H J heat energy, light energy, and sound light energy and sound energy only. heat energy and sound energy only. heat energy only. 13 Expectation: 6.9(C) A computer monitor transforms electrical energy into A B C D mechanical energy and heat chemical energy and nuclear light energy and heat sound energy and nuclear 14 Expectation: 6.9(C) An oven transforms electrical energy into F nuclear energy and mechanical G heat energy and light H chemical energy and sound 3 light energy and sound Progress Testing Page 6

10 8th Grade Science 6.9C 15 Expectation: 6.9(C) A water wheel transforms mechanical energy into A nuclear B light C chemical D electrical Progress Testing Page 7

11 8th Grade Science 6.9C Name Class/Grade Date DIRECTIONS FOR MARKING ANSWER SHEET Use a #2 pencil only. Do NOT use ink or ballpoint pens. Make heavy black marks that fill the ovals completely. Erase clearly any answer you wish to change. Make no stray marks on the answer sheet. O OCD O CD g 0(Dgg (1) g OCD 0 O CD g OCDOCD OCD 0 Cl CD(DED O CDOCD O gg OSCDg Progress Testing

12 8th Grade Science 6.9C Instructions to read aloud to your students. When you decide what the answer to a question is, mark your answer on your answer sheet. To do so, find the row of circles with the same number as the question. Then darken in the circle with the same letter as the answer you chose. If you don't know the answer to a question, skip it. You may return to it later if you have time. If you finish the test early, you should go back and check over your work. Do NOT fold your answer sheet or make any stray marks. When marking your answer sheet: 1. Make a heavy mark. The mark should be large enough to fill the circle, but it should not go outside too much. Do not waste time making very neat marks. It is more important to make very dark marks. Be sure to use a #2 pencil. 2. Be sure that your mark for every question is placed in the row with the same number as that question. 3. Make only ONE mark in a row. If you change your mind about an answer, erase your first mark as completely as you can. O 0 CP gg 0 O CD 0 O fbg CD 011g8 O CD@CD 0 g 00 CDC)g 0 (DOg g 4) 0 CD 8 (1)

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14 Name: Teacher: Pd. Date: STAAR Science Tutorial 17 TEK 6.9C: Energy Forms & Conversions TEK 6.9C: Demonstrate energy transformations such as energy in a flashlight battery changes from chemical energy to electrical energy to light Energy Forms Energy is the ability to do work or cause change. Unlike matter, energy does not have mass or take up space. It is visible only through the motion of matter or other changes to matter that it causes. As discussed in Tutorial 13: Potential and Kinetic Energy, energy can be classified into two broad categories, kinetic energy (energy presently performing work) and potential energy (stored energy not presently performing work). Energy can also be classified by its energy form, the physical appearance that it takes when observed interacting with matter. Energy form is a different classification category from the kinetic-potential classification category. Just as people can be classified by gender (male or female), age or by race, so too can energy be classified both by form, as discussed in this tutorial, and by its active or stored state, as discussed in Tutorial 13. Energy is found in six different forms: mechanical energy, chemical energy, thermal energy, electrical energy, radiant (or electromagnetic) energy, and nuclear energy: Mechanical energy, in its kinetic, working state, is the energy of motion of large objects, or the motion of a mass of particles moving in unison. A moving car, wind, ocean wave, earthquake or sound wave are all examples of kinetic mechanical In the potential, stored state, mechanical energy is the energy stored in large objects or a mass of particles, because of their position, such as height above the ground (gravitational potential energy), or stored in its internal condition, such as compression or tension (elastic potential energy). A body of water stored behind a high dam, and a roller coaster car sitting at the top of the hill, are examples of gravitational potential A compressed spring, stretched rubber band, and deformed rock along a fault line, which when released causes an earthquake, are all examples of elastic potential mechanical Chemical energy is the energy stored in the bonds between atoms, such as ionic or covalent bonds. Chemical energy is always potential energy, never kinetic energy, because the chemical energy form must be converted to another form before it can do work or be observed as causing change. Every chemical reaction either stores chemical energy (endothermic reactions) or releases energy (exothermic reactions). The photosynthesis chemical

15 reaction in plants uses radiant energy from sunlight and converts and stores that energy in the atomic bonds within the sugar created by the plant. When that sugar is eaten by an animal and digested, the cellular respiration reaction breaks the atomic bonds in sugar and converts the chemical energy, usually into thermal energy or mechanical Thermal energy is the energy of vibrational motion in atoms and molecules. The greater the rate of vibration, the greater the thermal energy the particles have. Thermal energy is measured as temperature. Any atom or molecule above absolute zero (-273 C) has thermal The vibration of thermal energy is why substances have a melting point and a boiling point. Matter with low thermal energy is found as a solid there is not enough vibration (thermal energy) to allow the atoms to move around in relation to one another. As the thermal energy increases, the atoms vibrate more and can move around more easily the solid melts into a liquid. As still more thermal energy is added, the atoms vibrate so violently that they can leave their container and fly around as a gas. Most energy transformation processes eventually produce thermal energy as the final energy form. Electrical energy is the energy found in charged particles protons (+) or electrons (-). If the charges are not moving, we call it static electricity (potential energy). Examples of static electrical energy are the charge a person picks up when walking across carpet, charges in a cloud just before a lightning discharge, and the charge stored in a capacitor in an electrical circuit. If the particles (usually electrons) are moving through a conductor, it is an electrical current (kinetic energy). Electrical energy is easy to transport, and can easily be converted into other energy forms. For this reason, modern civilization is built around electric generation and electrical devices such as motors and computers. Radiant or electromagnetic energy is the only form of energy that does not need matter to be transmitted. Radio waves, microwaves, infrared waves, visible light, ultraviolet light, x-rays and gamma rays are all types of radiant or electromagnetic energy, differing only in their wavelengths. Electromagnetic waves move at a very fast constant speed (the "speed of light"), and thus can only be kinetic, not potential, Nuclear energy is the energy stored in the nucleus of atoms released either in the nuclear fusion (fusing two nuclei into one nucleus) or fission (breaking one nucleus into two nuclei). The sun uses nuclear fusion to create other energy forms. Nuclear electric power plants use nuclear fission to create other energy forms. Law of Conservation of Energy The law of conservation of energy states that energy cannot be destroyed, but only transformed (converted) into different forms. For example, when sunlight (radiant energy) falls on a plant, the chlorophyll within the plant converts the radiant energy into chemical energy, stored in the atomic bonds of the sugar produced by photosynthesis. The mechanical energy of motion, such as in a roller

16 coaster car, is usually transformed into thermal energy by friction (a force that opposes motion). Energy Transformations In stars and our Sun, nuclear energy is transformed by the nuclear fusion process (fusing four hydrogen nuclei into one helium nucleus) into electromagnetic / radiant This electromagnetic (radiant) energy can travel through the vacuum of space to Earth, where it is transformed (converted) into other energy forms. Sunlight, which is electromagnetic / radiant energy, strikes the Earth's surface and greenhouse gas molecules in the atmosphere, and are transformed into thermal energy, as the Earth is warmed by sunlight. As thermal energy is transferred by conduction from the land surface to air molecules, the air becomes less dense and rises, thus transforming some of the thermal energy into mechanical energy (convection currents and wind). When sunlight (electromagnetic / radiant energy) falls on a plant leave containing chlorophyll, the radiant energy is converted into chemical energy stored in the chemical bonds between the atoms in sugar, assembled from the carbon, oxygen and hydrogen atoms from water and carbon dioxide. This is the photosynthesis reaction. When animals eat plants and the sugar they contain, the chemical energy is converted into either mechanical energy (movement of the animal) or thermal energy (body heat). A small amount of the chemical energy is also converted into electrical energy for the nervous system. Some animals, such as fireflies and deep-sea fish, can convert chemical energy into light (electromagnetic energy). In a flashlight, chemical energy in the batteries is converted to electrical energy when the circuit including the batteries, switch and light bulb is completed. The electrical energy is converted to light (electromagnetic / radiant energy) and some heat (thermal energy) by the light bulb. In an electric motor, electrical energy is converted to motion (mechanical energy) and some heat (thermal energy). In a gasoline engine such as those found in an automobile, the chemical energy in the gasoline is converted into thermal energy (heat) when it burns, which in turn expands the gases in the cylinder and turns the engine (mechanical energy), moving the car. In a wind-powered electric generator, the wind (mechanical energy) turns the propeller, which then turns the electric generator, converting mechanical energy into electrical

17 In a coal- or natural gas-powered electric generator, the chemical energy contained in the coal or natural gas is converted into thermal energy, which moves the turbine (mechanical energy), which turns the electric generator, creating electrical In a nuclear-powered electric generator, nuclear energy in the uranium (rather than the chemical energy in coal or natural gas) is converted to thermal Practice Questions 1. The ability to do work or cause change is called 2. The two main categories of energy are energy (stored energy) and work or causing change). 3. The form of energy that is found in large moving objects is energy (energy presently doing 4. The form of energy that is stored in large objects because of its position above the ground is 5. The form of energy that is stored in large objects because of its internal condition, such as compression or tension, is called 6. The form of energy stored in the bonds between atoms is 7. The form of energy stored in the nucleus of atoms is 8. Light and radio are examples of the or energy form. 9. Moving electrons in a conductor are an example of 10. Vibrating molecules and atoms are an example of 11. The two kinds of nuclear reactions are and 12. In a roller coaster, both the kinetic and potential energy in the car decreases at each successive hill because of energy into, which converts

18 13. The energy transformation in the Sun is from to 14. The energy conversion that causes wind is from energy in to energy in the wind. 15. The energy transformation in a flashlight is from energy contained in the battery to energy in the circuit, to and energy released by the light bulb. 16. The energy transformation in photosynthesis is from energy from to energy made by the chlorophyll in the plant. 17. The energy transformation in cellular respiration is from in the food that animals eat into the motion and energy of their body heat. energy of their