Structure of Matter

1. Structure of Matter Physical Science-Grade 9, Chemistry MSTP Region 11 Teacher Center Today’s Trainers: Anne Loyle, Gillian Roehrig, Abdi Warfa University of Minnesota

2. Overview of Workshops • Day 1: Force and Motion • PLC C • Day 2: Energy • PLC D • Day 3: Structure of Matter • PLC A • Day 4: Chemical Reactions • PLC B • Day 5: Sharing and Celebration

3. Agenda • Pre-test • Overview of Next Generation Standards • Periodic Table Activity • Density of Metals Activity • Chemistry Inquiry Activity • Nature of Science Activity • History of the Atom • Representations in Chemistry and Periodic Table Revisited • Overview of PLC A

4. Assessment • IRB permission • Pre-test

5. Objectives • Explore how to integrate the practices of science (inquiry) into chemistry • Explore how to integrate crosscutting concepts into chemistry • Explore the role of different representations in chemistry

6. MN State Standards Nature of Science & Engineering

7. Next Generation Science Standards Crosscutting Themes • Patterns • Cause and effect: Mechanism and explanation • Scale, proportion, and quantity • Systems and system models • Energy and matter: Flows, cycles, and conservation • Structure and function • Stability and change

8. Practices of Science

9. Inquiry into the Periodic Table Mendeleev sorted the elements using atomic weight and reactivity of 63 elements In teams work with one set of cards to create an organizational structure that uses atomic weight and reactivity to group the elements

10. Inquiry into the Periodic Table

11. Inquiry into the Periodic Table • Which card best fits into the gap in your Periodic Table? What would you add to the three empty corners of the card? Ge 62.7 Ge 62.7 Ge 66.0 Ge 72.6 Ge 72.6

12. Inquiry into the Periodic Table

13. Inquiry into the Periodic Table

14. Inquiry into the Periodic Table

15. Was this lesson inquiry?

16. Lab Activity on Density of Metals • How is the atomic number of metallic elements related to their density? • Plan: • Hypothesis formation: Working in groups of 3, generate hypothesis based on data in Table 1 • Data Collection: Collect experimental data to test hypothesis • Accept/Rejection Hypothesis: based on collected data, accept or reject initial hypothesis …

17. Trends in the Density of 2nd Raw Transition Metals

18. Trends in the Density of Transition Metals

19. Representations in Chemistry HCl + NH3 → NH4Cl Macroscopic Symbolic Particulate

20. Inquiry in Chemistry • Why does the water level rise? • Set up the experiment and make detailed observations. • Write an explanation and draw a model to explain what caused the water to rise

21. Inquiry in Chemistry • After listening to each group’s explanation write out your formal hypothesis and test your hypothesis. • Share your results and revised explanation/model on your whiteboard

22. Inquiry in Chemistry • Testing the “Oxygen Depletion” Model • There is a limited amount of oxygen in the tube. So two candles might deplete the oxygen more quickly but will deplete the same amount of oxygen as one candle. • Therefore if the “oxygen depletion” model is accurate the water level when two candles are burned will be the same as when one candle is burned. • If the water level is higher for two candles than one candle then the “oxygen depletion” model is disproved.

23. Inquiry in Chemistry • Charles’ Law: Temperature of a gas is directly proportional to volume. • Kinetic Molecular Theory: gases are composed of many small molecules that are in constant, random motion. • http://phet.colorado.edu/en/simulation/gas-properties

24. Representations in Chemistry HCl + NH3 → NH4Cl Macroscopic Symbolic Particulate

25. Nature of Science: Observations • Please observe setup in the front • Write down your observations • Share your observations with you neighbor

26. Nature of Science: Observation and Inference • Observation: • Our perception of an object or an event, using as many senses as possible. • Inference: • Reasonable explanation that we construct on the basis of our observations. • Science as a Way of Knowing: • Scientific knowledge if based on observation and inference

27. Nature of Science: Black Box Activity • Rule: You cannot open the box • Investigate the behavior of the black box. • What do you think is inside your black box? • Record your observations in your notebook. • Make inferences about what you think is inside your black box and draw a picture.

28. Nature of Science: Black Box Activity • Meet with a group and discuss the diagram that you drew. • Resolve any disagreements • You will need to come up with one agreed upon diagram. • Choose one person to draw you diagram on the whiteboard.

29. Nature of Science: Black Box Activity • Now that you have seen the models, here are the four options – teacher info.

30. The History of the Atom (the classic black box!) • Physicists in that late 1800s and early 1900s debated the nature of cathode rays • But what is the nature of these cathode rays?

31. History of the atom • Cathode rays produced shadows just like light. • Cathode rays are waves? • Cathode rays moved a paddle wheel along the tube • Cathode rays are small particles?

32. History of the atom • J.J. Thomson hypothesis was that cathode rays were charged particles • He tested this hypothesis by passing the cathode ray between electrically charged plates. Negatively charged plate Positively charged plate

33. History of the atom • If cathode rays are negatively charged particles they will be attracted to the positive plate • If cathode rays are neutral waves they will not be deflected by the electrical plates.

34. History of the atom • Thomson wanted to know more! What was the mass of this particle? How big was the electrical charge? • Bold Conclusion: Atoms were made up of smaller parts! By investigating the relationship between the charge across the electric plates and the degree of deflection of the cathode beam he conclude that the particles had tiny mass and “normal” charge Regardless of the metal used to generate the cathode ray the same result occurred.

35. History of the atom • Draw a picture of an atom based on the new information discovered by J.J. Thomson

36. History of the atom • Rutherford: experimenting with the behavior of alpha particles (large, positively charged particles) • Fired alpha particles into thin gold foil The deflection of some particles back toward the source was unexpected. Why did this happen?

37. History of the atom • Rutherford did not start his experiment with a hypothesis about the structure of the atom. However, he used this unexpected result to propose a new structure for the atom If Thomson’s model were accurate then all of the alpha particles should go through the foil – Rutherford’s data disproves Thomson’s model Rutherford proposed a new model with compact, positively charged nucleus. This model was empirically supported by his data

38. Periodic Table Revisited Macroscopic Symbolic Particulate

39. Periodic Table Revisited • Why do alkali metals become more reactive as you go down the group? • Explain the trend below in atomic size

40. Periodic Table Revisited • Explain the trend for ionization energy

41. Debrief: Crosscutting Themes • Patterns • Cause and effect: Mechanism and explanation • Scale, proportion, and quantity • Systems and system models • Energy and matter: Flows, cycles, and conservation • Structure and function • Stability and change

42. Debrief: Practices of Science • Asking questions (for science) and defining problems (for engineering) • Developing and using models • Planning and carrying out investigations • Analyzing and interpreting data • Using mathematics and computational thinking • Constructing explanations (for science) and designing solutions (for engineering) • Engaging in argument from evidence • Obtaining, evaluating, and communicating information

43. Overview of PLC A

44. Exit Slip • What new ideas do you have about teaching chemistry this year? • What questions do you have about integrating the practices of science? Crosscutting themes? Representations of chemistry? • Anything else that you would like to share with the MSTP Instruction Team • Turn this in as you leave.