1. Electronic Behavior of Atoms

2. LO Describe how light is created. Explain how wavelengths of light relate to energy levels in the atom. SC View the spectrum of hydrogen. Interpret changes in electron energies in the hydrogen atom to develop an explanation for where the colored light in the hydrogen spectrum comes from. Use Bohr’s model of the atom to predict parts of the hydrogen- atom spectrum. Compare the wavelengths, energies, and frequencies of light of different colors. Identify regions in the electromagnetic spectrum. Explain the photoelectric effect. Do Now Grade 1.4 Quiz Copy LO and SC WDYS, WDYT p. 35 Agenda WDYS, WDYT Investigation Chem Talk Summary

3. Read through and complete numbers 1 and 2 You MUST draw diagrams with what you see that include the colors

5. Complete numbers 3 and 4 on pg. 36 Be ready to discuss as a class!

6. Complete numbers 5-9, reading through each of the explanations and answering the questions. Pay close attention to the diagram on p. 38

7. LO Describe how light is created. Explain how wavelengths of light relate to energy levels in the atom. SC View the spectrum of hydrogen. Interpret changes in electron energies in the hydrogen atom to develop an explanation for where the colored light in the hydrogen spectrum comes from. Use Bohr’s model of the atom to predict parts of the hydrogen- atom spectrum. Compare the wavelengths, energies, and frequencies of light of different colors. Identify regions in the electromagnetic spectrum. Explain the photoelectric effect. Do Now Copy LO and SC WDYS, WDYT p. 35 Agenda WDYS, WDYT Investigation Chem Talk Summary

8. Skim through the chem talk on p. 39 Do not take notes!

9. http://player.discoveryeducation.com /index.cfm?guidAssetId=0D2CCF17- 8C4E-4101-A1FF-D11305F6878C Watch first 5 minutes

10. Who was Niels Bohr? What did he discover?

11. Who was Niels Bohr? What did he discover? A Danish Physicist He thought that electrons took a circular orbit around an atom and that they jump between energy levels while taking in energy and forming light

14. What is light What is frequency?

15. What is light What is frequency? Photons, or packets of energy, that travel in waves. Come from energy level transfers

16. What is light What is frequency? Photons, or packets of energy, that travel in waves. Come from energy level transfers The number of cycles per second, measured in Hz usually

17. What is wavelength What is the speed of light?

18. What is wavelength What is the speed of light? The distance from crest to crest in a wave.

19. What is wavelength What is the speed of light? The distance from crest to crest in a wave. 3x10 8 m/s, and it is constant!

21. How do we calculate frequency using wavelength?

22. How are wavelength and energy related?

23. They are inversely related! As E increases, the wavelength gets smaller!

24. What are photons? How can we calculate frequency from energy?

25. What are photons? How can we calculate frequency from energy? Fixed packets of energy with a specific wavelength.

26. What are photons? How can we calculate frequency from energy? Fixed packets of energy with a specific wavelength. Where h is plancks constant: 6.63x10 - 34 J  s

27. What is the photoelectric effect?

28. When light collides with an atom, it interacts with an electron, causing it to be thrown off of the atom due to the fixed amount of energy of the photon.

29. What were the weaknesses of the Bohr Model?

30. 1.It could only account for the light transitions of the Hydrogen atom 2.Could not explain why some transitions were allowed while others were not.

31. What is the frequency of light that has a wavelength of 432.4nm?

32. Using Planck’s constant, what is the energy of red light?

33. In hydrogen the energy change of an electron jumping from E 3 to E 2 is 3.03 x 10 -19 J What is the frequency? What is the wavelength? (and therefore color)

34. Complete the checking up questions.

35. Essential Questions, p. 42 --How do you know? --Why do you believe --Why should you care LO and SC reflection