Inquiry-based Practical Chemistry & its Assessment 探究為本化學實驗的推行及評估

1. Inquiry-based Practical Chemistry & its Assessment探究為本化學實驗的推行及評估 5 Nov 2005 Science Education Section EDB

2. Programme

3. Scientific Inquiry • Inquiry - an active engaging process that mimics the work done by actual scientists. • Require students to design some or all of the procedures (ownership and motivation): autonomy • Increase the opportunities for students to think about the data they should collect and their presentation • Lead to a deeper understanding of scientific concepts • In guided inquiry, students • choose what data to be collected • design the procedures to address the question for investigation • In open inquiry, students make almost all the decisions including the questions for investigation

4. Scientific Inquiry • “The diverse ways in which scientists study the natural world and propose explanations based on the evidence from their work.” • “The activities through which students develop knowledge and understanding of scientific ideas, as well as an understanding of how scientists study natural world.” US National Science Education Standardshttp://www.nap.edu/readingroom/books/nses/html/pdf/index.html

5. Scientific Enquiry • http://www.standards.dfes.gov.uk/keystage3/respub/sc_enquiry • National Curriculum Handbook for Teacher • DfES, UK

6. “Inquiry-based teaching engages students in investigations to satisfy curiosities, with curiosities being satisfied when individuals have constructed mental frameworks that adequately explain their experiences.” • “Inquiry-based teaching begins or at least involves stimulating curiosity or provoking wonder. There is no authentic investigation or meaningful learning if there is no inquiring mindseeking an answer, solution, explanation, or decision.”

7. Types of Scientific Enquiry • Surveys and correlations (pattern seeking) • Controlling variables (fair test) • Identification and classification • Using and evaluating a technique • Technology (make something or invent a system to solve the problem) • Using experimental models and analogies to explore an explanation, hypothesis or theory • Using secondary sources →appropriate approach to solve the problem

8. Goldsworthy A, Watson R, & Robinson V W (2000) Developing Understanding in Scientific Enquiry, ASE • Sang D & Robinson V W (2002) Teaching Secondary Scientific Enquiry, ASE

9. Authentic Investigations that are Meaningful to Students • Drain Cleaners • Mosquitoes repellants • Antioxidants in fruits and tea • Vitamin C in fruits and drinks (Does Ribena contain 4 times the vitamin C of oranges?) • Biodiesel from vegetable oils • Fuel cell from pencil and aluminium can • Hot cup and fever eliminator • Preventing corrosion of metals • Colour-safe bleach • Skin whitening cream • Tooth whitening strip • Chloride content in foodstuffs • Prevent metal from corrosion (e.g. bridge, wok)

10. Quantitative Investigations • Do iron tablets deteriorate? • Titration of iron(II) sulphate with KMnO4 • The salt content of different foods • Titration of chloride ions with AgNO3 using KCrO4 as indicator • Chlorine in swimming pools

11. Qualitative Investigations • Oxygen-absorber (脫氧劑/脫酸素劑) present in packages of moon-cakes • Find out the chemical species responsible for oxygen absorption • Simple chemical tests

12. Preparative Investigations • Biodiesel • Energy crisis • Demonstrate the green chemistry principle of using renewable resources • Prepare biodiesel from vegetable oils • Compare properties with other fuels • http://www.chemsoc.org/networks/learnnet/green/biodiesel/home.htm

13. Amazing Miracle • Use milk in making • Plastic • Glue • Invisible glove • Photographic film • Fire resistant paint

14. A B T-shaped tube container with essential oil container with distilled water bottle containing mosquitoes Natural Mosquito Repellant from Fruit Peels • Mosquito-borne diseases e.g. Dengue fever, Japanese encephalitis • N,N-diethyl-3-methylbenzamide (DEET) 避蚊胺 • Terpineol in fruit peels • Fradin, M.S. & Day, J. F. (2002)Comparative Efficacy of Insect Repellents against Mosquito Bites. New England J. of Medicine. 347(1), pp.13-18 http://content.nejm.org/cgi/content/full/347/1/13

15. Design and Make Investigations • Using enthalpy changes for heating and cooling in camping • Design and make a self-heating can to heat the coffee contained in a standard size can to 65oC and to maintain it at this temperature for up to 30 minutes • Design and make • a pocket hand-warmer • a system that could be used to keep drink cool

16. Aluminium-Air Fuel Cell • Construct useful things from waste materials • Design and construct an aluminium-air fuel cell from soft drink cans • Investigate the current produced with different electrolytes • Investigate the cell e.m.f. and current produced with different metal anodes • http://www.ectechnic.co.uk/fuelcell.html

17. Fair Tests • Investigating the effects of varying fuels and electrolytes on the electrical energy generated in an alkaline fuel cell • http://chem.hku.hk/~fuelcell/demo.htm • Further investigations on electrochemical cells: • determine the concentration of unknown solution • potentiometric titration

18. Menthos and Cola • Adds a "Menthos" type candy to a glass of soda pop. Students observe an increase in "fizz" or release in carbon dioxide. • Possible explanations? • Investigations: different candies / cola, no. of candies, temp, container, shape of candy • http://www.consumptionjunction.com/downloadsnew/cj_49646.wmv • http://www.scienceman.com/scienceinaction/pgs/demo_9u2_01.html

19. CD-ROM Possible Chemistry Investigations

20. Laboratory Investigations • http://chem.lapeer.org/Chem2Docs/Index.html

21. Problem-solving Activities • http://www.chemsoc.org/networks/learnnet/rscpubs.htm • In Search of Solutions • Egg Races (enjoyable, competitive, practical problem-solving activities which required some application of chemical principles); free download • In Search of More Solutions

22. Investigation Sheets • http://www.york.ac.uk/org/seg/salters/chemistry/ResourceSheets/rsindex.html • Background, Practical Techniques, Where to Start, Possible Investigations, Source of Information, Teacher Notes

23. Teachers’ role • Choose activities that match students’ background knowledge and reasoning skills • Communicate effectively to students what the educational purposes of the investigation (learning of scientific process and answering the question being investigated) • Challenging students to defend the quality of their evidence and arguments • Creating an environment in which students become critical of their own and others’ evidence • Expose students’ thinking and make it more accessible to discussion and development using displayed questions or variable tables, etc

24. Questioning • Strategies for helping students ask questions • Provide students with an observable phenomenon to ask questions about • Have students read articles regarding interesting happenings in science • Suggest possible topics for investigation (a list of possible investigations) e.g. How much NaOCl is found in commercial bleaches and how does it compare to the claimed? Edwards, C H(1997)

25. From Cookbook to Inquiry • Transition to inquiry-based instruction by implementing changes gradually e.g. remove the data table • Shifting toward guided and open inquiry by continuing to remove the supports of the activity • Assessment should stress goals in scientific reasoning and critical thinking in addition to content knowledge • Assess students’ abilities to generate open-ended and researchable queries, devise scientific procedure, interpret data

26. Assessment • Achievement level matrixes in internal assessment of International Baccalaureate (IB) • 2 aspects apply to data collection (collecting and recording raw data; organizing and presenting raw data), data processing and presentation, and manipulative skills • 3 aspects apply to planning, conclusion and evaluation, personal skills

27. References • Baumgartner E. (2004). Student Poster Sessions. The Science Teacher. March, pp. 39-41. • Colburn, A. (2004). Inquiry scientists wants to know. Educational Leadership. 62, pp.63-66. • Colburn, A. (1997). How to make lab activities more open ended. CSTA Journal, pp.4-6. • Edwards, C. H. (1997). Promoting Student Inquiry. The Science Teacher. 64 (7). pp.18-21. • Lechtanski, V.L. (2000). Inquiry-based Experiments in Chemistry. New York: Oxford University Press. • Lunsford, E. & Melear, C. T. (2004). Using scoring rubrics to evaluate inquiry. J. of College Science Teaching, Sept. • 侯傑泰 (2004)《 專題研究手冊初級版》香港:朗文。 • 侯傑泰 (2004)《 專題研究手冊進階版》香港:朗文。

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