Do Now

1. Do Now When the bell rings Respond to the following: “The secret of getting ahead is getting started.” -Mark Twain After the bell (2 min) • In your seat: • With pen/pencil • With Notebook • With Handout (from last class) • Silent and ready for Do Now

2.  • Do Now (5 min) • Announcements/Test Scores (5 min) • Reflection (5 min) • Remediation Topic (5min) • Warm Up (5 min) • Highlights of atomic theory history (20 min) • Theory v. Law (5 min) • Independent Practice (10 min) • Exit Slip (5 min) • Closing (2 min) Agenda

3. Remediation Topic: How? Identify the use of each piece of lab equipment (use your reference sheet to guide you) Graduated cylinder Erlenmeyer Flask Graduate beaker Tongs Dropper What? • C – None • H – Raise hand • A – Identifying Lab Equipment • M – None • P – Answering questions to the right, recording responses on left page, discussing with group each prompt

4. The History of the AtomDay #2 Objectives: Differentiate between theory and law Understand the history of the atomic theory Create a timeline that shows the changes in the atomic theory over time Summarize the results from Rutherford’s experiment and identify the role of the cathode ray in the discovery of the atom

5. Warm Up How? Using your notes from last class place the following list of key contributors to atomic theory in order of appearance What? (5 min) • C – Whispers • H – Raise hand • A – Answer with group, • M – None • P – Record responses on reverse side of page. Dalton Thomson Rutherford Heisenberg Democritus Chadwick Bohr Schrodinger Milliken de Broglie Seaborg

6. 1941-1951: Seaborg discovers transuranium elements Our Timeline 400 BC: Democritus theorizes the concept of “atomos” 1911: Rutherford’s Gold Foil Experiment (+ nucleus) 1930: Schrodinger’s wave model 1897: Thomson’s Cathode Ray Tube (electron) 1923: De Broglie discovers wave nature of electrons 1909: Millikan’s Oil Drop Experiment (electron is negative) 1927: Heisenberg’s Uncertainty Principal 1803: John Dalton’s atomic theory The Father of Modern Atomic Theory 1932: Chadwick discovers Neutron 1922: Bohr’s Model

7. Watch the following video: • Bill Nye • Answer the following: • If atoms are mostly empty space, why don’t they break when we stand on them? • What is in the nucleus? How far are electrons from the nucleus? • What do you get when you combine atoms? • How can you demonstrate the spaces between molecules of water? What Is An Atom?

8. 4 Key Components we need to understand • Law of Definite Proportions • Rutherford’s experiment • JJ Thomson’s Cathode Ray Tube Experiment • Continuous Development Putting it Together

9. Also known as Proust’s Law • Definition: When two elements combine to form a compound, they do so in a definite proportion by mass. • Ex: H2O = 2:16  1:8 • Mass of Hydrogen: 1 amu x 2 (2 atoms of H) • Mass of Oxygen: 16 amu Law of Definite Proportions

10. Cathode Ray Tube Experiment • Discovered the electron JJ Thomson’s Cathode Ray Tube = =

11. Discovered the positively charged nucleus • Rutherford Animation Rutherford’s Gold Foil Experiment Prediction Reality

12. Science builds upon discovery • Every new development in our understanding came by building on or disproving a previous model • Our atomic model is only built on 200 years of science • It is not complete (see Quarks) Continuous Development

13. Activity: Independent Practice How? 10 minutes  Discuss for 5 minutes  Verify & Review All rows and columns add up to the same number What? • C – None • H – Raise hand • A –Answering questions about atomic theory history • M – None • P – Recoding answers on provided page, head up, reading and thinking through all questions, discussing with group

14. Exit Slip How? If you finish early, summarize what you learned at the bottom of your notes OR answer today’s guiding question What? (5 min) • C – No talking • H – Raise hand • A – Taking exit slip • M – In seat • P – Completing exit slip without notes and turning in

15. Forgetting to stretch is a bear. • What are 3 key takeaways from today and yesterday? • Complete the 4 Stretch questions • Be ready to discuss the structure of the atom next class Closing