1. The Structure of an Atom

2. What is alchemy? Ancient chemists

3. What did alchemists try to do? Find the philosophers stone, turn things to gold, and make fireworks

4. Who was the first person to come up with the word atom? Democritus

5. What did he say? The world was made up of tiny, indivisible particles (atomos).

6. Who was the next guy to come along in chemistry? John Dalton

7. What did John Dalton say? He had his atomic theory.

8. What is a theory? It is a explanation as to why an experiment may give certain results.

9. What is a law? A short statement explaining what will happen in a given situation.

10. What is the difference between a theory and a law? Laws are SHORT descriptions. Theories are LONG explanations.

11. What is Dalton’s Atomic Theory? It explains Democritus' laws.

12. How many parts of the atomic theory are there? 5 Johnny 5 is alive!

13. What is the first part? All matter is made of atoms.

14. The second? Atoms of different elements differ by their mass, size and other properties.

15. The third? Atoms cannot be created, destroyed, or divided.

16. The fourth? Compounds contain more than one atom.

17. The fifth? Chemical reactions require atoms to combine, separate, or rearrange.

18. How was Dalton wrong? Atoms are actually divisible All atoms of an element are not identical.

19. What is an atom? A piece of matter that can not be broken down any further and still have the characteristics of the element.

20. How small is an atom? So small we can’t even take a picture of it.

21. If you made an atom the size of an orange, you would have to make an orange the size of the earth to keep scale!

22. How Small is the Atom? https://youtu.be/yQP4UJhNn0I

23. Who was the first guy to prove atoms could be broken down into smaller pieces? J.J. Thomson

24. What did he do? Discover the electron.

25. How did he do that? He was playing with electricity and matter.

26. What tool did he use? A cathode ray tube.

27. Cathode Ray Tube https://www.youtube.com/watch?v=O9Goy scbazk

28. How did he arrive at his conclusion? He figured out there were negatively charged particles in an atom.

29. What did he call these negatively charged particles? Electrons.

30. Where did he think electrons were located? All throughout the atom. The plum pudding model

31. What was discovered next? Protons.

32. Who did that? Ernest Rutherford

33. How did Rutherford discover protons? The Gold Foil Test

34. https://www.youtube.com/watch?v=zUtIrO 3fUgg https://www.youtube.com/watch?v=zUtIrO 3fUgg

35. Where are protons located? In the center of the atom.

36. What else did Rutherford discover? The nucleus

37. How big is the nucleus compared to the rest of the atom? Very small (the size of a quarter if the atoms is the size of a football stadium)

39. How did that change the way they thought an atom looked? The nucleus is now in the middle of the sphere. Electrons are on the outside.

40. What is the charge of a proton? Positive

41. How does the size of a proton compare to an electron? A proton is about 1836 times larger.

42. What is the other part of an atom? Neutrons.

43. What charge do they have? None-neutral

44. How big are they? About the same size as a proton

45. What hold the protons and neutrons together? Nuclear forces

46. What do the neutrons do? Are kind of like the glue for the protons.

47. To Find Protons: Look up the Atomic Number of the Element

48. To Find Electrons: Equal to the number of protons

49. To find Neutrons: Round Mass to Whole Number!!! mass – number = neutrons

50. Who was the next scientist to change how the atom looked? Neils Bohr

51. What did Neils Bohr say? The atom has electrons that orbit the atom, like the planets orbit the sun.

52. What are the paths the electrons travel on called? Energy levels

53. How do I figure out how many electrons go on each energy level? Use the periods on the periodic table.

55. What is the period? The energy levels

56. What is the number of elements in each period? The number of electrons that can fit in the energy level.

57. How many can fit in each energy level? 1-2 2-8 3-8 4-18 5-18 6-32 7-32

58. Why 32? The two rows at the bottom of the periodic table are misplaced.

59. What is a valence electron? The number of electrons in the outermost energy level.

60. What is the current atomic theory? The quantum model.

61. What is the electron cloud model? That electrons are in clouds instead of set paths.

62. Who came up with this theory? Ernest Schrödinger

63. What is the quantum based off of? Electrons actually move so fast, it is impossible to know their exact location. He used an equation

64. Where can we find electrons? In clouds or regions.

65. What is an isotope? An atom that has different numbers of neutrons

66. Do the isotopes of the same atoms all act the same? Yes! The only difference is the number of neutrons

67. What is the ONLY difference between isotopes? The numbers of neutrons

68. What is the mass number? Exact mass of the atom Mass number = protons + neutrons

69. Aluminium-27 27 Al Al-27 The 27 is the MASS NUMBER!

71. What is the difference between the mass given in an isotope and the atomic mass on the periodic table? An isotope gives the exact mass. The PT is an average of all the known isotopes.

72. How do I find the most common isotope of an atom? By using the rounded mass from the periodic table.

73. Look it up! What is the most common isotope of…  Oxygen  Tin  Calcium  Bromine  Tungsten

74. What is average atomic mass? The weighted average mass of all the common isotopes of an atom. (RA x Mass) + (RA x Mass) + (RA x Mass)= RA is Relative Abundance

75. (RA x Mass)+(RA x Mass)+(RA x Mass)….= RA is Relative Abundance 1. Turn percent to a decimal (move 2 places) to turn to RA. 2. Multiply mass by RA 3. Add each isotope together to get atomic mass.

76. What unit is used for atomic mass or mass number? Atomic mass unit (amu)