Bell Ringer

1. Bell Ringer Which scientist is credited with the discovery of electrons by experimenting with Cathode Ray Tubes?

2. Atomic Structure Notes

3. Atomic Structure subatomic particles Atoms are made up of __________ _________ . neutrons protons Subatomic particles include ________, _________ and _________. electrons ________ and _________ are inside the ________ Protons neutrons nucleus __________ are found __________ the nucleus Electrons outside

4. Subatomic Particles Protons have a _________ charge and a mass of ________. + 1 AMU 1 AMU = Atomic Mass Unit neutral Neutrons have a _________ charge and a mass of _________. 1 AMU - Electrons have a _________ charge and a mass that is so ______ that we consider electrons to have ____ mass! small “NO”

5. Number of Protons Elements in the Periodic Table are organized by ________ ________. Atomic number The atomic number is the same as the number of ________. protons different Every element has a _________ number of protons, and therefore a ________ atomic number. different

6. Atomic Number = # protons

7. Number of Electrons In a _________ atom, the number of _________ always equals the number of __________. neutral protons electrons #p = #e

8. Electron Practice Find the number of protons and electrons in the following atoms: 12 12 8 8 79 79 22 22

9. Atomic Mass An atom’s mass is the sum of its parts 1 Proton = ________ amu 1 Neutron = ________ amu 0 Electron = ________ amu Since the electron has practically no mass we don’t count it in the mass of the atom

10. Atomic Mass You can find the mass of an atom from the __________ _______ Periodic Table For us, that mass is the sum of the __________ and __________ . Neutrons Protons 9 Fluorine has - __________ protons 19 __________ neutrons

11. Atomic Mass = # protons + # neutrons

12. Number of Neutrons To get the number of neutrons, get the atomic mass from the _________ ______ and subtract from that the number of ________. Periodic Table protons #neutrons = Atomic Mass - #p

13. Neutron Practice Find the number of p, n and e in the following atoms: 11 12 11 5 5 6 0 1 1 6 6 6

15. Atomic Structure wkst Textbook Packet

16. Bell Ringer How many neutrons does a lead atom have?

17. Qz: Atomic Structure

18. Element Symbols Every element has a _________ on the Periodic Table. symbol The symbol is either 1 or 2 letters, where the first is always a _________ letter, and the second is always a _______ letter… CAPITAL small C He Ca H

19. Element Notation Element symbols contain the atomic number, mass number and element symbol. J Mass number Element symbol Atomic number

20. Element Notation Complete the notation for the following: K Al 39 27 13 19

21. Atomic Structure wkst Textbook Packet coninued

22. Bell Ringer Identify the atom that has 26 neutrons, 22 protons and 22 electrons.

23. BELL RINGER Draw the electron dot diagrams for Chlorine and Sodium.

24. BELL RINGER How many electrons does a phosphorus atom have? Neutrons?

25. BELL RINGER Draw the Bohr diagrams for Lithium and Oxygen.

26. The Bohr Model Basic Layout The ________ is in the center of the atom and contains both _________ and __________, and the ___________ are found orbiting the nucleus. nucleus protons electrons neutrons

27. Electron Energy Levels • Electrons are found in _______ levels around the nucleus. energy • The _______ to the nucleus, the ________ the energy of the electrons. lower closer • The _______ from the nucleus, the ________ the energy of the electrons. farther higher

28. Electron Configuration Electron configuration is the ___________ of electrons outside the nucleus of an atom. arrangement The 1st energy level holds up to ____ electrons. 2 2ndlevel holds up to ___ 8 3rdlevel holds up to ___ 18

29. Electron Configuration You don’t have to memorize this, use the Periodic Table Look under the atomic number and you will see where the electrons will go For Oxygen, there are ___ electrons in the 1st level and ___ electrons in the 2nd level. 2 6

30. How to: Bohr Models Rules protons nucleus 1. Put the number of _______ in the ________ neutrons 2. Put the number of _________ in the ________ nucleus 3. Put a dot for each electron in the ______ energy level (Max of __ ) and then move on to the second if necessary. first 2 second 5. Put a dot for each electron in the _______ energy level (Max of __ ) and then move to the third if necessary. 8 6. Repeat for the third level if necessary

31. Practice: Bohr Models Li Draw the Nucleus – make sure it is big enough to write inside Add the protons and neutrons to the nucleus Draw the first energy level and put a dot for each electron on that level (Max of 2) Draw the second energy level and put a dot for each electron on that level (Max of 8) 3p Notice the yellow electrons – these are Valence Electrons (e- on the outermost shell) 4n

32. Practice: Bohr Models Al Draw the Nucleus – make sure it is big enough to write inside Add the protons and neutrons to the nucleus Draw the first energy level and put a dot for each electron on that level (Max of 2) Draw the second energy level and put a dot for each electron on that level (Max of 8) Draw the third energy level and put a dot for each electron on that level (Max of 18) Notice the yellow electrons – these are Valence Electrons (e- on the outermost shell) 13p 14n

33. Bohr Diagram wkst

34. Bell Ringer Draw the Bohr diagram for an atom of Aluminum.

35. Review: Valence Electrons What are they? Electrons on the outermost energy level Why are they important? They are the only electrons involved in chemical reactions How do you know how many an atom has? On the Periodic table, below the atomic number

36. Lewis Dot Diagrams Electron Dot diagrams, (also called ______ Dot diagrams) show only the _________ electrons in an atom. Lewis valence It includes the ______________ and the _______ of valence electrons. element symbol number Let’s figure out the ‘rules’ for drawing Lewis/Electron Dot Diagrams…

37. Rules - Lewis Dot Diagrams 1. The first __ valence electrons go on the _____ side of the element symbol. 2 top H He

38. Rules - Lewis Dot Diagrams 2. Electrons are added ____ at a time in a _________ direction as seen below. one clockwise J 2 1 8 3 5 6 4 7

39. Practice

40. p= n= 9 10 Bell Ringer Identify the atom above

41. Electron Movement

42. Electron Energy We already learned that electrons are located on specific _______ ______ outside the nucleus levels energy The electrons closer to the nucleus have ______ energy and need to _______ energy to get farther away from the nucleus. absorb lower

43. Electron Movement When you look on the periodic table, you get the _______ state electron configuration ground heat electrical If exposed to enough _____ or __________ energy, electrons can _______ energy and jump up an energy level and become ______. absorb excited

44. Electron Movement The excited state is __________, and really quickly the electron will _____ back down to where it came from and give off the energy it absorbed. temporary drop Think of a young kid after eating candy!

45. Energy Released Electrons will release energy as ______. light Since each energy level jump has a different _______ of energy, the energy given off will be a different ______ of light. amount color

46. Normal Light White light is made of ____ the colors of the _________. all spectrum Passing light through a ______ separates the light into individual ________ – each having its own ______________. prism colors wavelength

47. Bright-Line Spectra Each element gives off different ________ of energy – this produces a unique _______ of ______ and ________ that we call a __________ spectrum. n = 4 amounts n = 3 pattern lines n = 2 colors bright-line n = 1

48. Bright-line Spectra They are formed when atoms ______ (give off) __________. emit energy Each element produces a ________ pattern. unique

49. Unknown Spectra

50. Flame Test lab