DOCSLIB.ORG

Teaching H. C. Ørsted's Scientific Work in Danish High School Physics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Teaching H. C. Ørsted's Scientific Work in Danish High School Physics UNIVERSITY OF COPENHAGEN FACULTY OF SCIENCE Ida Marie Monberg Hindsholm Teaching H. C. Ørsted's Scientific Work in Danish High School Physics Masterʹs thesis Department of Science Education 19 July 2018 Master's thesis Teaching H. C. Ørsted’s Scientific Work in Danish High School Physics Submitted 19 July 2018 Author Ida Marie Monberg Hindsholm, B.Sc. E-mail [email protected] Departments Niels Bohr Institute, University of Copenhagen Department of Science Education, University of Copenhagen Main supervisor Ricardo Avelar Sotomaior Karam, Associate Professor, Department of Science Education, University of Copenhagen Co-supervisor Steen Harle Hansen, Associate Professor, Niels Bohr Institute, University of Copenhagen 1 Contents 1 Introduction . 1 2 The Material: H. C. Ørsted's Work . 3 2.1 The Life of Hans Christian Ørsted . 3 2.2 Ørsted’s Metaphysical Framework: The Dynamical Sys- tem............................. 6 2.3 Ritter and the failure in Paris . 9 2.4 Ørsted’s work with acoustic and electric figures . 12 2.5 The discovery of electromagnetism . 16 2.6 What I Use for the Teaching Sequence . 19 3 Didactic Theory . 20 3.1 Constructivist teaching . 20 3.2 Inquiry Teaching . 22 3.3 HIPST . 24 4 The Purpose and Design of the Teaching Sequence . 27 4.1 Factual details and lesson plan . 28 5 Analysis of Transcripts and Writings . 40 5.1 Method of Analysis . 40 5.2 Practical Problems . 41 5.3 Reading Original Ørsted's Texts . 42 5.4 Inquiry and Experiments . 43 5.5 "Role play" - Thinking like Ørsted . 48 5.6 The Reflection Corner . 51 5.7 Evaluation: The Learning Objectives . 53 5.8 Advice for designing a sequence on HPS . 58 6 Discussion: Is Teaching HPS a Relevant Option in Danish High School Physics? . 60 6.1 My own Results . 61 6.2 The Inclusion of HPS in High School Physics . 63 7 Conclusion . 66 2 Appendices 73 A Writing Exercise 74 B Text about Ørsted's Dynamic System 75 C Experimental Guide: Voltaic Battery 77 D Ørsted’s Aesthetic 80 E Experimental Guide: Electricity and the Magnetic Needle 81 F Transcription of the Lessons 83 G Answers to Writing Exercises 111 3 Abstract There is an apparent paradox in the way the history and philosophy of science (HPS) is viewed in science teaching: On one hand it is supported by research as a central approach to teaching methodology and nature of science (NoS), but on the other hand there is very little actual implementation of HPS in science teaching on all levels. This master project is a case study in developing and teaching an HPS sequence to a Danish high school physics class, in order to find the central obstacles and advantages that this approach has. The aim of the sequence is to shift focus in physics teaching from facts and finished models to science as a process, and thereby to teach the students a more nuanced view on how scientific knowledge is created. The theoretical basis is a constructivist view on learning and an inquiry based approach to experiments. The project is inspired by the results and strategies of a large European research project on HPS (HIPST) and uses concrete strategies from this project, where emphasis is laid on experimental work, reconstruction of historical apparatus, and interpreting data in rela- tion to a specific philosophical framework. I have chosen the case of H. C. Ørsted’s scientific work as content, focusing on his experimental work and metaphysical ideas about electricity. H. C. Ørsted was guided by romanti- cism and Naturphilosophie in all of his scientific research, and through his career he experienced failures and mistakes before his great success in dis- covering electromagnetism, which makes him very suitable for the aim of my sequence. I have undertaken a qualitative analysis of transcripts of the lessons and of open writing exercises given to the students before and after the sequence. Based on the results from this I conclude that the overall idea of using HPS to teach about the NoS aspects is fully applicable and that the strategies presented by HIPST were mostly effective for the students' learning and reflection about science. A point to be improved in future use of the sequence was that it did not stress the importance of mathematical descriptions in science. In the end, I discuss how HPS can play a bigger role in Danish high school teaching in general. The main suggestion is that the curriculum could support this more fully by presenting ideas for concrete implementation of HPS. 1 Introduction In Denmark as well as in most European countries, history and philosophy of science (HPS) is not a field that takes up a lot of space in high school cur- ricula and textbooks. According to larger studies in this area (see H¨ottecke and Silva 2011 [1]) there are several reasons for this, many of which relate to tradition and subject culture: Many science teachers have never been edu- cated in HPS, and they tend to view it as a peripheral part of their subject that should not take time from the modern factual explanations of specific scientific phenomena. There are, however, according to research in didactics important things to be gained from implementing a historic and philosophic view in science teaching. Many researchers in science education have argued (see for instance [2{4]) that HPS is a fruitful approach to teaching and learning about the aspects of science that are not hard facts and mathematical models, but related to processes and methodology. And recently the European project HIPST (History and Philosophy in Science Teaching) has aimed at providing research based tools and teaching material in the field of HPS through several case studies in 8 different countries. The project presented in this thesis is a case study inspired by HIPST. I have developed and tested a teaching sequence about the scientific work of Hans Christian Ørsted to a b-level physics class in high school, in order to examine the central obstacles and advantages that this approach has in physics teaching. The sequence is centred around the question: How is scien- tific knowledge created?. The students have reflected on this general question through repetition and interpretation of H. C. Ørsted’s most important ex- periments, with the objective of giving them a more nuanced understanding of the scientific process and methodology - especially in physics. The hope is that the students after the sequence will view physics not as the collection of facts and finished models that they are often presented to in class, but also as a process. A process of mistakes and blind-alleys which is constantly interacting with society and culture. Based on the results from HIPST I propose the idea that a historic case study is an effective way to study these aspects of physics which are all related to what is often called "the nature of science" (NoS). From a constructivist perspective, scientists and students are in similar situations: They want to discover a certain knowledge which is often related to a specific problem. But traditional content focused teaching (in the worst case) tends to give the final answer to the problem before the students have had a chance of discovering anything. Instead they are left to do "cookbook" experiments where they follow a given procedure to obtain a knowledge they had already 1 been told beforehand. This way they learn nothing about how the scientific process actually works, and the school subject becomes very different to the research subject. As opposed to this approach, the historic case study shows the process of scientific discovery and even lets the students participate in it as they follow in the tracks of a working scientist. The choice of H.C. Ørsted as case has several reasons. Firstly, he is an example of a scientist who was devoted to a very specific philosophical viewpoint (romanticism) which guided him in all of his research and was perhaps the cause of both his biggest mistakes and his main achievement of discovering electromagnetism. This makes him suitable for studying the relationship between science and culture as well as the important roles of mistakes in physics. Secondly he is one of the most famous Danes worldwide but at the same time he is rather underexposed in Danish culture and most people know nothing about him apart from his discovery of electromagnetism. Thirdly, his experiments are not technically challenging and do not demand rare equipment which make them easy to repeat with the students. Apart from this he was simply a fascinating character who viewed science and the physical world in a way which seems extremely strange today, but did turn out to be very productive anyway. In my design of the teaching sequence I intend to incorporate these central aspects of Ørsted’s work in student centred activities such as group discus- sions, experimenting and reading of Ørsted’s original publications. My basic viewpoint in this design is constructivism as an approach to describe and understand the learning process. More specifically this means that I have used different inquiry-strategies in my design and focused on activities that allow the students to generate their own knowledge through interaction with didactical milieu. In this thesis I start out by presenting Ørsted’s philosophy and work in section 2 since it is the foundation of the material and probably not very well known by most physics teachers. In section 3 I describe constructivism and the inquiry approach to learning, followed by an introduction to the more concrete strategies proposed by the HIPST project. In section 4 I provide a detailed overview of the purpose and design of the sequence lesson by lesson, including the didactic considerations.
Load more

Recommended publications
  • Printer Tech Tips—Cause & Effects of Static Electricity in Paper
    Printer Tech Tips Cause & Effects of Static Electricity in Paper Problem The paper has developed a static electrical charge causing an abnormal sheet-to- sheet or sheet-to-material attraction which is difficult to separate. This condition may result in feeder trip-offs, print voids from surface contamination, ink offset, Sappi Printer Technical Service or poor sheet jog in the delivery. 877 SappiHelp (727 7443) Description Static electricity is defined as a non-moving, non-flowing electrical charge or in simple terms, electricity at rest. Static electricity becomes visible and dynamic during the brief moment it sparks a discharge and for that instant it’s no longer at rest. Lightning is the result of static discharge as is the shock you receive just before contacting a grounded object during unusually dry weather. Matter is composed of atoms, which in turn are composed of protons, neutrons, and electrons. The number of protons and neutrons, which make up the atoms nucleus, determine the type of material. Electrons orbit the nucleus and balance the electrical charge of the protons. When both negative and positive are equal, the charge of the balanced atom is neutral. If electrons are removed or added to this configuration, the overall charge becomes either negative or positive resulting in an unbalanced atom. Materials with high conductivity, such as steel, are called conductors and maintain neutrality because their electrons can move freely from atom to atom to balance any applied charges. Therefore, conductors can dissipate static when properly grounded. Non-conductive materials, or insulators such as plastic and wood, have the opposite property as their electrons can not move freely to maintain balance.
    [Show full text]
  • Introduction to Direct Current (DC) Theory
    PDHonline Course E235 (4 PDH) Electrical Fundamentals - Introduction to Direct Current (DC) Theory Instructor: A. Bhatia, B.E. 2012 PDH Online | PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030-6658 Phone & Fax: 703-988-0088 www.PDHonline.org www.PDHcenter.com An Approved Continuing Education Provider CHAPTER 3 DIRECT CURRENT LEARNING OBJECTIVES Upon completing this chapter, you will be able to: 1. Identify the term schematic diagram and identify the components in a circuit from a simple schematic diagram. 2. State the equation for Ohm's law and describe the effects on current caused by changes in a circuit. 3. Given simple graphs of current versus power and voltage versus power, determine the value of circuit power for a given current and voltage. 4. Identify the term power, and state three formulas for computing power. 5. Compute circuit and component power in series, parallel, and combination circuits. 6. Compute the efficiency of an electrical device. 7. Solve for unknown quantities of resistance, current, and voltage in a series circuit. 8. Describe how voltage polarities are assigned to the voltage drops across resistors when Kirchhoff's voltage law is used. 9. State the voltage at the reference point in a circuit. 10. Define open and short circuits and describe their effects on a circuit. 11. State the meaning of the term source resistance and describe its effect on a circuit. 12. Describe in terms of circuit values the circuit condition needed for maximum power transfer. 13. Compute efficiency of power transfer in a circuit. 14. Solve for unknown quantities of resistance, current, and voltage in a parallel circuit.
    [Show full text]
  • Steel Production Through Electrolysis: Impacts for Electricity Consumption 0, 0, 75
    Font Family: Benton Sans 131, 176, 70 Steel production through electrolysis: impacts for electricity consumption 0, 0, 75 204, 102, 51 Adam Rauwerdink 144, 144, 144 VP, Business Development October 18, 2019 Font Family: A 3,000 year old formula Benton Sans Iron Ore Carbon (Coal) Iron Carbon Dioxide 131, 176, 70 Fe2O3 C Fe CO2 0, 0, 75 204, 102, 51 >2 144, 144, 144 Gt CO2 per year (8% of global emissions) Iron Age 1000 BC Digital Age 2019 2 Boston Metal | 2019 Font Family: Steel in 2018 Benton Sans 131, 176, 70 Aluminium is #2 at 1,800 64 million tonnes 0, 0, 75 million tonnes 204, 102, 51 70% 30% 144, 144, 144 Integrated Steel Mill Mini Mill (Iron ore new steel units) (Scrap recycled steel units) Source: World Steel Association 3 Boston Metal | 2019 Font Family: Integrated steel mill: material flow Benton Sans 131, 176, 70 0, 0, 75 204, 102, 51 144, 144, 144 4 Boston Metal | 2019 Font Family: Molten oxide electrolysis (MOE) is emissions free Benton Sans Molten Oxide Electrolysis (MOE) 131, 176, 70 Iron Ore Electricity Iron Oxygen 0, 0, 75 - Fe2O3 e Fe O2 204, 102, 51 144, 144, 144 No carbon in the process = No CO2 emitted Electricity decarbonization eliminates/reduces indirect emissions! 5 Boston Metal | 2019 Font Family: Changing the formula from coal to electricity Benton Sans Iron Ore Carbon (Coal) Iron Carbon Dioxide 131, 176, 70 Fe2O3 C Fe CO2 0, 0, 75 204, 102, 51 Molten Oxide Electrolysis (MOE) 144, 144, 144 Iron Ore Electricity Iron Oxygen - Fe2O3 e Fe O2 6 Boston Metal | 2019 Font Family: MOE is more energy efficient Benton
    [Show full text]
  • A Dc–Dc Converter with High-Voltage Step-Up Ratio and Reduced- Voltage Stress for Renewable Energy Generation Systems
    A DC–DC CONVERTER WITH HIGH-VOLTAGE STEP-UP RATIO AND REDUCED- VOLTAGE STRESS FOR RENEWABLE ENERGY GENERATION SYSTEMS A Dissertation by Satya Veera Pavan Kumar Maddukuri Master of Science, University of Greenwich, UK, 2012 Bachelor of Technology, Jawaharlal Nehru Technology University Kakinada, India, 2010 Submitted to the Department of Electrical Engineering and Computer Science and the faculty of the Graduate School of Wichita State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2018 1 © Copyright 2018 by Satya Veera Pavan Kumar Maddukuri All Rights Reserved 1 A DC–DC CONVERTER WITH HIGH-VOLTAGE STEP-UP RATIO AND REDUCED- VOLTAGE STRESS FOR RENEWABLE ENERGY GENERATION SYSTEMS The following faculty members have examined the final copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirement for the degree of Doctor of Philosophy with a major in Electrical Engineering and Computer Science. ___________________________________ Aravinthan Visvakumar, Committee Chair ___________________________________ M. Edwin Sawan, Committee Member ___________________________________ Ward T. Jewell, Committee Member ___________________________________ Chengzong Pang, Committee Member ___________________________________ Thomas K. Delillo, Committee Member Accepted for the College of Engineering ___________________________________ Steven Skinner, Interim Dean Accepted for the Graduate School ___________________________________ Dennis Livesay, Dean iii DEDICATION To my parents, my wife, my in-laws, my teachers, and my dear friends iv ACKNOWLEDGMENTS Firstly, I would like to express my sincere gratitude to my advisor Dr. Aravinthan Visvakumar for the continuous support of my PhD study and related research, for his thoughtful patience, motivation, and immense knowledge. His guidance helped me in all the time of research and writing of this dissertation.
    [Show full text]
  • Instructor's Guide
    Instructor’s Guide Electricity: A 3-D Animated Demonstration ELECTRICITY AND MAGNETISM Introduction This instructor’s guide provides information to help you get the most out of Electricity and Magnetism, part of the eight-part series Electricity: A 3-D Animated Demonstration. The series makes the principles of electricity easier to understand and discuss. The series includes Electrostatics; Electric Current; Ohm's Law; Circuits; Power and Efficiency; Electricity and Magnetism; Electric Motors; and Electric Generators. Electricity and Magnetism traces the relationship between magnetism and electricity from the first accidental discovery of induced current. Learning Objectives After watching the video program, students will be able to: • Describe the relationship between electricity and magnetism • Explain the difference between electric and magnetic fields • Explain the construct, function, and use of solenoids • Differentiate between, explain, and apply the left-hand and right-hand rules • Demonstrate (via experiments) and explain aspects, and actions and functions of electricity, magnetism, and electromagnetism Educational Standards National Science Standards This program correlates with the National Science Education Standards from the National Academies of Science, and Project 2061, from the American Association for the Advancement of Science. Copyright © 2008 SHOPWARE® • www.shopware-usa.com • 1-800-487-3392 Electricity: A 3-D Animated Demonstration ELECTRICITY AND MAGNETISM INSTRUCTOR’S GUIDE Science as Inquiry Content Standard A:
    [Show full text]
  • Faraday's Law Da
    Faraday's Law dA B B r r Φ≡B •d A B ∫ dΦ ε= − B dt Faraday’s Law of Induction r r Recall the definition of magnetic flux is ΦB =B∫ ⋅ d A Faraday’s Law is the induced EMF in a closed loop equal the negative of the time derivative of magnetic flux change in the loop, d r r dΦ ε= −B∫ d ⋅= A − B dt dt Constant B field, changing B field, no induced EMF causes induced EMF in loop in loop Getting the sign EMF in Faraday’s Law of Induction Define the loop and an area vector, A, who magnitude is the Area and whose direction normal to the surface. A The choice of vector A direction defines the direction of EMF with a right hand rule. Your thumb in A direction and then your fingers point to positive EMF direction. Lenz’s Law – easier way! The direction of any magnetic induction effect is such as to oppose the cause of the effect. ⇒ Convenient method to determine I direction Heinrich Friedrich Example if an external magnetic field on a loop Emil Lenz is increasing, the induced current creates a field opposite that reduces the net field. (1804-1865) Example if an external magnetic field on a loop is decreasing, the induced current creates a field parallel to the that tends to increase the net field. Incredible shrinking loop: a circular loop of wire with a magnetic flux is shrinking with time. In which direction is the induced current? (a) There is none. (b) CW.
    [Show full text]
  • Electrochemistry of Fuel Cell - Kouichi Takizawa
    ENERGY CARRIERS AND CONVERSION SYSTEMS – Vol. II - Electrochemistry of Fuel Cell - Kouichi Takizawa ELECTROCHEMISTRY OF FUEL CELL Kouichi Takizawa Tokyo Electric Power Company, Tokyo, Japan Keywords : electrochemistry, fuel cell, electrochemical reaction, chemical energy, anode, cathode, electrolyte, Nernst equation, hydrogen-oxygen fuel cell, electromotive force Contents 1. Introduction 2. Principle of Electricity Generation by Fuel Cells 3. Electricity Generation Characteristics of Fuel Cells 4. Fuel Cell Efficiency Glossary Bibliography Biographical Sketch Summary Fuel cells are devices that utilize electrochemical reactions to generate electric power. They are believed to give a significant impact on the future energy system. In particular, when hydrogen can be generated from renewable energy resources, it is certain that the fuel cell should play a significant role. Even today, some types of fuel cells have been already used in practical applications such as combined heat and power generation applications and space vehicle applications. Though research and development activities are still required, the fuel cell technology is one of the most important technologies that allow us to draw the environment friendly society in the twenty-first century. This section describes the general introduction of fuel cell technology with a brief overview of the principle of fuel cells and their historical background. 1. Introduction A fuel cellUNESCO is a system of electric power – generation,EOLSS which utilizes electrochemical reactions. It can produce electric power by inducing both a reaction to oxidize hydrogen obtained by reforming natural gas or other fuels, and a reaction to reduce oxygen in the air, each occurringSAMPLE at separate electrodes conne CHAPTERScted to an external circuit.
    [Show full text]
  • AC Vs. DC Boost Converters: a Detailed Conduction Loss Comparison
    AC vs. DC Boost Converters: A Detailed Conduction Loss Comparison Daniel L Gerber Fariborz Musavi Building Technology and Urban Systems Engineering and Computer Science Lawrence Berkeley Labs Washington State University Berkeley, CA, USA Vancouver, WA, USA [email protected] [email protected] Abstract—Studies have shown the efficiency benefits of DC dis- at the same voltage. Although several previous works have tribution systems are largely due to the superior performance of analyzed and established loss models for the DC/DC [9]– DC/DC converters. Nonetheless, these studies are often based on [12] and AC/DC PFC [13]–[20] boost converters, they each product data that differs widely in manufacturer and operating have their own methods and formulae, making an analytic voltage. This work develops a rigorous loss model to theoretically comparison difficult. In addition, many of them neglect es- compare the efficiency of a DC/DC and an AC/DC PFC boost sential components such as the input bridge drop and output converter. It ensures each converter has the same components and equivalent operating voltages. The results show AC boost capacitor equivalent series resistance (ESR). This is the first converters below 500 W to have 2.9 to 4.2 times the loss of DC. work to establish a set of formulae that compare the loss between an AC and DC boost converter, both of which have the Keywords—DC microgrid, boost converter, loss model, power same components and equivalent operating voltages. Although factor correction DC/DC converters are already known to be more efficient, this work reports exactly how much more.
    [Show full text]
  • Faraday's Law Da
    Faraday's Law dA B B r r Φ≡B •d A B ∫ dΦ ε= − B dt Applications of Magnetic Induction • AC Generator – Water turns wheel Æ rotates magnet Æ changes flux Æ induces emf Æ drives current • “Dynamic” Microphones (E.g., some telephones) – Sound Æ oscillating pressure waves Æ oscillating [diaphragm + coil] Æ oscillating magnetic flux Æ oscillating induced emf Æ oscillating current in wire Question: Do dynamic microphones need a battery? More Applications of Magnetic Induction • Tape / Hard Drive / ZIP Readout – Tiny coil responds to change in flux as the magnetic domains (encoding 0’s or 1’s) go by. 2007 Nobel Prize!!!!!!!! Giant Magnetoresistance • Credit Card Reader – Must swipe card Æ generates changing flux – Faster swipe Æ bigger signal More Applications of Magnetic Induction • Magnetic Levitation (Maglev) Trains – Induced surface (“eddy”) currents produce field in opposite direction Æ Repels magnet Æ Levitates train S N rails “eddy” current – Maglev trains today can travel up to 310 mph Æ Twice the speed of Amtrak’s fastest conventional train! – May eventually use superconducting loops to produce B-field Æ No power dissipation in resistance of wires! Faraday’s Law of Induction r r Recall the definition of magnetic flux is ΦB =B∫ ⋅ d A Faraday’s Law is the induced EMF in a closed loop equal the negative of the time derivative of magnetic flux change in the loop, d r r dΦ ε= −B∫ d ⋅= A − B dt dt Constant B field, changing B field, no induced EMF causes induced EMF in loop in loop Getting the sign EMF in Faraday’s Law of Induction Define the loop and an area vector, A, who magnitude is the Area and whose direction normal to the surface.
    [Show full text]
  • Materials That Cause Static Electricity
    Materials that Cause Static Electricity http://www.school-for-champions.com/science/static_materials.htm Some materials cause or create more static electricity than others. Since static electricity is the collection of electrically charged particles on the surface of a material, various materials have a tendency of either giving up electrons and becoming positive (+) in charge or attracting electrons and becoming negative (−) in charge. The Triboelectric Series is a list of materials, showing which have a greater tendency to become positive (+) and which have a greater tendency to become negative (−). The list is a handy tool to determine which combinations of materials create the most static electricity. Questions you may have include: What are materials in the Triboelectric Series? What are the best combinations of materials? What are acceptable combinations? Triboelectric Series Common materials are listed according how well they create static electricity when rubbed with another material, as well as what charge the material will possess. Become positive in charge The following materials will tend to give up electrons when brought in contact with other materials. They are listed from those with the greatest tendency to give electrons to those that barely give up electrons. Materials that gain a positive (+) electrical charge (or tend to give up electrons) Greatest tendency to giving up electrons and becoming highly positive (+) in Dry human skin charge Leather Rabbit fur Fur is often used to create static electricity Glass The glass on your TV screen gets charged and collects dust Human hair "Flyaway hair" is a good example of having a moderate positive (+) charge Nylon Wool Lead A surprise that lead would collect as much static electricity as cat fur Cat fur Silk Aluminum Gives up some electrons Paper Neutral There are very few materials that do not tend to readily attract or give up electrons when brought in contact or rubbed with other materials.
    [Show full text]
  • Electrochemistry –An Oxidizing Agent Is a Species That Oxidizes Another Species; It Is Itself Reduced
    Oxidation-Reduction Reactions Chapter 17 • Describing Oxidation-Reduction Reactions Electrochemistry –An oxidizing agent is a species that oxidizes another species; it is itself reduced. –A reducing agent is a species that reduces another species; it is itself oxidized. Loss of 2 e-1 oxidation reducing agent +2 +2 Fe( s) + Cu (aq) → Fe (aq) + Cu( s) oxidizing agent Gain of 2 e-1 reduction Skeleton Oxidation-Reduction Equations Electrochemistry ! Identify what species is being oxidized (this will be the “reducing agent”) ! Identify what species is being •The study of the interchange of reduced (this will be the “oxidizing agent”) chemical and electrical energy. ! What species result from the oxidation and reduction? ! Does the reaction occur in acidic or basic solution? 2+ - 3+ 2+ Fe (aq) + MnO4 (aq) 6 Fe (aq) + Mn (aq) Steps in Balancing Oxidation-Reduction Review of Terms Equations in Acidic solutions 1. Assign oxidation numbers to • oxidation-reduction (redox) each atom so that you know reaction: involves a transfer of what is oxidized and what is electrons from the reducing agent to reduced 2. Split the skeleton equation into the oxidizing agent. two half-reactions-one for the oxidation reaction (element • oxidation: loss of electrons increases in oxidation number) and one for the reduction (element decreases in oxidation • reduction: gain of electrons number) 2+ 3+ - 2+ Fe (aq) º Fe (aq) MnO4 (aq) º Mn (aq) 1 3. Complete and balance each half reaction Galvanic Cell a. Balance all atoms except O and H 2+ 3+ - 2+ (Voltaic Cell) Fe (aq) º Fe (aq) MnO4 (aq) º Mn (aq) b.
    [Show full text]
  • When You Pull a Wool Sweater Over Your Head, You Might Look Like This
    NAME__________________ 6. Who discovered that lightning was a form of Science SOL 4.3 – Electricity electricity? www.solpass.org a. Thomas Edison b. Benjamin Franklin When you pull a wool sweater quickly c. Michael Faraday over your head, you might look like this. When Electric current powers many things in our homes. your feet rub the carpet before you touch a metal Current electricity is the flow of electrons through a doorknob you might get a shock or see a spark. conductor. Most home appliances need current electricity Why? Static electricity. Static electricity is the running through an electrical circuit in order to work. An open circuit is a circuit with a break in it that will result of electrons being pulled from not allow the flow of electrons. A closed circuit allows the one surface to another when two objects flow of electrons. rub together. This can happen if you take off a sweater too fast or when you 7. A(n) ______ will allow the flow of electricity. scuff your feet on the carpet. Your feet pick up extra electrons a. open circuit from the carpet and become negatively charged. Those electrons jump off your finger as a spark when your finger comes close to a b. closed circuit metal object like a doorknob. 8. The diagram shows a(n) 1. Which of the following creates static electricity? a. closed a. Taking a bath circuit b. Plugging a power cord into the wall outlet. b. open c. Rubbing feet on the carpet. circuit 2. What might cause foam 9.
    [Show full text]