1. 100 200 300 400 500 100 200 300 400 500 100 200 300 400 500 100 200 300 400 500 100 200 300 400 500 HistoryAtomsIons & Isotopes NuclearLAB Work

2. How many significant figures in the number 204 for 100 Who was the first person to believe that matter was made of tiny discrete particles called ‘atomos’?

3. Answer for 100: Democritus

4. Explanation (100) Democritus His ideas were not accepted at the time but come back and were revived much later in time.

5. for 200 Fill in the blank with the appropriate sketch, and the name of the scientist that proposed this model of the atom.

6. Answer for 200 Fill in the blank with the appropriate sketch, and the name of the scientist that proposed this model of the atom. Thomson + + + + - - - -

7. Explanation (200) In the late 1800 ’ s Thomson is given credit for “ discovering ” the electron and putting forth what is sometimes called the “ chocolate chip cookie ” model of the atom.

8. for 300 What was the name of the experiment used to “ discover ” the nucleus. Why were the men Rutherford invited over to see his experiment so shocked?

9. Answer for 300: What was the name of the experiment used to “ discover ” the nucleus. Why were the men Rutherford invited over to see his experiment so shocked? The gold foil experiment. The men were shocked because the alpha particle should have blasted right through the foil, and it bounced back instead due to the nucleus.

10. Explanation (300) The gold foil was very thin and the alpha particle should have blasted right through Thomson ’ s model, but Rutherford proposed the existence of a very small dense nucleus.

11. for 400 What knowledge of the atom was determined using this instrument? AND what is this instruments name?

12. Answer for 400 What knowledge of the atom was determined using this instrument? The discovery of the electron and its charge. Cathode Ray Tube

13. Explanation (400) The movement of the beam by a magnet indicated it was negatively charged particles.

14. for 500 Which idea was NOT a part of Dalton’s Atomic theory? 1. All elements are made of tiny particles called atoms 2. All atoms of a given element are identical 3. Atoms chemically combine with different atoms to form compounds 4. Atoms can not be created nor destroyed in chemical reactions 5. Neutral atoms contain equal numbers of protons and electrons

15. Answer for 500 Number 5 is NOT part of Dalton’s atomic theory

16. Explanation (500) Although the statement Neutral atoms contain equal numbers of protons and electrons is true for most atoms (not ions which we now know exist) it is not part of Dalton’s theory

17. for 100 State the number of protons, neutrons and electrons in the most common isotope of 28 Ni atoms.

18. Answer for 100 State the number of protons, neutrons and electrons in the most common isotope of 28 Ni atoms. 28 protons 28 electrons 31 neutrons

19. Explanation (100) The atomic number 28 tells us protons and electrons for atoms. Mass # 59 - 28 tell us the 31 neutrons.

20. for 200 What is the difference in meaning between the numbers in the symbols: 1 H and 4 He and Cl -1 ?

21. Answer for 200 What is the difference in meaning between the numbers in the symbols: 1 H and 4 He and Cl -1 ? 1 H is the atomic number = no. of protons. 4 He is the mass number = no. of protons + no. of neutrons Cl -1 is the charge. It tells you this atom has 1 extra electron

22. Explanation (200) Depending on where the number is and if it’s a subscript or superscript it tells you specific things about the atom

23. for 300 What is the name of the particle with 45 neutrons, 36 electrons, and 35 protons?

24. Answer for 300 What is the name of the particle with 45 neutrons, 36 electrons, and 35 protons? Bromine ion Br -1

25. Explanation (300) The 35 protons tells us the name of the element. The fact that there are a different number of electrons than protons tells us it is an ion.

26. for 400 Which subatomic particle(s) causes the mass of an atom and which subatomic particle(s) cause the size of an atom?

27. Answer for 400 Which subatomic particle(s) causes the mass of an atom and which subatomic particle(s) cause the size of an atom? The protons and neutrons cause the mass, the electrons cause the size.

28. Explanation (400) The electron weighs only 1/1840 th of a proton, yet its electron cloud is responsible for the size of the atom Even this representation of the relative small size of the nucleus compared to the rest of the large electron cloud is not dramatic enough.

29. for 500 How many protons, neutron, and electrons for 210 Po +3

30. Answer for 500 210 Po +3 Atomic number = 84p mass number = 210-84 = 126n charge = +3 = 81e

31. Explanation (500) Must use the mass number given and pay attention to any charges that may be present.

32. for 100 If an atom gains an electron what is the new particle called: anion, cation, or dogion?

33. Answer for 100 If an atom gains an electron what is the new particle called: anion, cation, or dogion? It is called an anion.

34. Explanation (100) Gaining an electron causes a negative ion called an anion. Losing electrons results in a positive ion called a cation. And this is a dogion !

35. for 200 There are 4 naturally occuring isotopes of tungsten; 182 W, 184 W, 185 W, and 186 W. Which is likely to be the most commonly occurring isotope?

36. Answer for 200 There are 4 naturally occuring isotopes of tungsten; 182 W, 184 W, 185 W, and 186 W. Which is likely to be the most commonly occurring isotope? It is likely to be 184 W.

37. Explanation (200) The % abundance found in nature weights the calculation of average mass.

38. for 300 State the number of protons, neutrons and electrons in Sr 2+

39. Answer for 300 State the number of protons, neutrons and electrons in Sr 2+ 38 protons 50 neutrons 36 electrons

40. Explanation (300) The name Sr tells you 38 protons. The mass number 88 - 38 = 50 neutrons. The 2+ charge indicates 2 electrons were lost resulting in 36 electrons.

41. for 400 If there are only two isotopes of silver; 107 Ag and 109 Ag, why isn ’ t the average atomic mass equal to 108?

42. Answer for 400 If there are only two isotopes of silver; 107 Ag and 109 Ag, why isn ’ t the average atomic mass equal to 108? Because the average mass is a weighted average. 56% is 107 Ag and only 44% of the silver is 109 Ag resulting in an average atomic mass that is closer to the lighter atom.

43. Explanation (400) It’s a weighted average so the average will be closer to the atom that is in a higher percentage.

44. for 500 What is the name of this element? 31 X

45. Answer for 500 What is the name of this element? 31 X It cannot be determined because this could be an isotope of any element such as Si, P, S, etc.

46. Explanation (500) You must be told the atomic number (or number of protons) to determine the identity of the element.

47. for 100 What does alpha (  ) decay look like? What is happeneing when something undergoes this type of decay?

48. Answer for 100 Looks like a Helium atom: 4 2 He The large atom decays and spits out a helium atom from it nucleus forming a new element.

49. Explanation (100) All elements #83 and beyond are radioactive and spew out the most protons and neutrons that it can at a time via alpha decay.

50. for 200 What is this emission particle called; 0 -1 e

51. Answer for 200 What is this emission particle called; 0 -1 e ? Beta or electron

52. Explanation (200) beta or negatively charged electron particle. It is emitted after a proton self-destructs into a neutron and spits out an electron.

53. for 300 What is gamma radiation? And when does it occur?

54. Answer for 300 What is gamma radiation? And when does it occur? Gamma radiation is high energy radiation that accompanies most other forms of nuclear decay.

55. Explanation (300) Gamma rays are not particles.

56. for 400 Write a reaction to represent the beta (  ) decay of 31 14 Si

57. Answer for 400 Write a reaction to represent the beta (  ) decay of 31 14 Si 31 14 Si ---> 0 -1 e + 31 15 P

58. Explanation (400) Compare the mass and atomic numbers before and after…they MUST be conserved

59. for 500 What is the new element and mass number when 244 Pu undergoes two alpha and a gamma decay?

60. Answer for 500 What is the new element and mass number when 244 Pu undergoes two alpha and a gamma decay? 244 Pu  4 2 He + 4 2 He + 0 0 y + 236 90 Th (Thourium)

61. Explanation (500) Make sure the mass and atomic numbers are conserved.

62. for 100 Explain the law of conservation of mass

63. Answer for 100 Mass can not be created nor destroyed in a chemical reaction, it only changes forms

64. Explanation (100) The mass of the reactants will equal the mass of the products in a chemical reaction

65. for 200 Name three indicators that a chemical reaction happened.

66. Answer for 200 1. color change 2. bubbles 3. solid forming

67. Explanation (200) These changes (and more) are clear indicators that some type of chemical change has occurred

68. for 300 If someone performs an experiment and gets a 70% percent error, is this a good result? EXPLAIN!

69. Answer for 300 BAD! We would like our percent error to be close to 0%

70. Explanation (300) If we have a high percent error it means that something seriously went wrong…perhaps an instrument error we were unaware of before starting the experiment.

71. for 400 How would we separate a mixture where our product was dissolved in a liquid?

72. Answer for 400 We could boil or evaporate the liquid and force the dissolved material to recrystallize into a solid.

73. Explanation (400) This is a simple separation technique we learned in Chapter 3!

74. for 500 For the law of conservation of mass lab (where we made that yellow material) we performed a double replacement reaction. The following is a similar reaction. Predict what the products will be if you start with the following reactants: Calcium nitrate + potassium sulfite  ? (Hint: calcium and potassium are (+) and nitrate and sulfite are (-) charges

75. Answer for 500 Double replacement is simply switching partners so simple switch the names making positive and negative charges combine Calcium nitrate + potassium sulfite  Calcium sulfite + potassium nitrate

76. Explanation (500) For these reactions we must dissolve the materials so they form ions and have an opportunity to react together and switch partners.

77. Place Your Bet.