Name: Block: ATOMIC MATH HOMEWORK True/False: Indicate if each of the following is true or false. If it is false, CHANGE the underlined portion to make it true. 1. In a neutral atom of an element, the number of protons always equals the number of electrons. 2. Atoms of elements are electrically neutral. 3. The mass number of an element is the sum of the protons and the electrons in the atom. 4. The mass of an electron is equal to a mass of a proton. 5. Atoms of the same element are similar in most ways, but they can differ in the number of protons in the nucleus. 6. The mass number of an element is the weighted average of the masses of the isotopes for that element. 7. The number of neutrons in an atom does not change the net charge, because neutrons are neutral. 8. In order for two atoms to be the same element, they must have the same number of electrons. Atomic Structure: 9. Draw a Bohr model of a helium-4 atom (include the 10. Compare & contrast: number of electrons, protons & neutrons 37 35 in the correct place). Cl Cl 17 17 Use terms & number of electrons, protons & neutrons 11. Fill in the following chart: (assume each atom is neutral). Element Complete Chemical Symbol Atomic Number Mass Number Number of protons Number of electrons Carbon 12 6 Number of neutrons K 19 21 12 25 4 2 2 8 9
Atomic Math: 12. Samples of an unknown element X were collected, and their masses were recorded. Use the following information presented in the data table to answer the following questions. Isotope Percent Abundance (%) X - 38 9.67 X - 39 78.68 X - 40 11.34 X - 41 0.310 a. What is the most common isotope for element X? Chemical Symbols: Write the complete nuclear symbol for the following: (assume neutral unless otherwise noted): 13. The atom that has 33 protons, 44 neutrons, and 33 electrons. 14. The element that has 20 protons and a mass number of 40. 15. A neutral potassium atom with a mass number of 39. 16. The atom with 29 protons, 29 electrons, and 36 neutrons. 17. Subatomic Particles: Determine the number of protons, electrons, and neutrons in each of the following: a.) 127 b.) 14 c.) 91 d.) 59 e.) S-34 I N Zr Ni 53 7 40 28 #p #p #p #p #p #e #e #e #e #e #n # n #n #n #n EARLY ATOMIC EXPERIMENTS & MODELS Scientists: Fill in the blank with the appropriate scientist. 18. I was the first to say that all matter is atomos, or indivisible made of solid, indestructible particles known as atoms! 19. I determined that all matter has two types of charge positive and negative. Opposite charges attract, and like charges repel! 20. I designed the first cathode tube, often named after me. I was the first to observe negatively charged particles in the tube! 21. Using a positive and negative plate placed above and below a CRT, I bent a cathode beam towards the positive plate, concluding it was made of negative particles. I also concluded that these electrons were part of the atom! 22. I measured the exact charge and mass of an electron using oil droplets!
23. I discovered positive particles by shooting electrons at hydrogen atoms in a cathode tube! 24. I showed that the atom actually had a nucleus, and that all of the positive charge was located there! 25. I determined that Thomson s model of the atom was incorrect. 26. Some of my ideas include: Elements are made of solid, indestructible particles known as atoms, and atoms of different elements look different! Concept Development: 27. What were the experimental results (what data was gathered) in Rutherford s Gold Foil Experiment? 28. How did the Gold Foil Experiment show that Thomson s model of the atom was incorrect? 29. How was the discovery of the neutron essential to understanding the stability of atoms? (Your answer should show your understanding of the structure of the atom) Reading the Periodic Table 30. What element is in the alkaline earth metals and in Period 5? 31. What element is the 4 th element in the Lanthanide series? 32. What element is a Halogen and liquid at room temperature? 33. What element is a gas at room temperature and in Period 4? 34. What element is a solid alkali metal in period 3? 35. What element is a transition element with 80 protons?
36. What element is a metalloid in the oxygen family? 37. What element is not a metal in the boron family? 38. What element is nonmetal in the Family 6? 39. What element has 2 valence electrons and is found in Period 6? Draw the Lewis Dot Diagram for the following elements: 40. Chlorine 41. Magnesium 42. Nickel 43. Krypton 44. Aluminum Periodic Table Families 45. Carbon Family 51. Actinide Series 46. Alkaline Earth Metals 52. Noble Gases 47. Lanthanide Series 53. Rare Earth Elements 48. Halogens 54. Nitrogen Family 49. Oxygen group 55. Transition metals 50. Alkali Metals A C 56. Boron Family D E B G H I J K L F M N O
Atomic Radius: Which atom in each pair has the LARGER atomic radius? Determine the reason and choose the appropriate reason code. Reason codes: A- It has additional energy levels, so it is larger. B- It has less nuclear charge which means the electrons are further from the nucleus, and the atoms is larger. C- Additional energy levels have a greater effect on size than an additional proton in the nucleus (increased nuclear charge) 1 57. Li or K Reason Code: 58. Ca or Ge Reason Code: 59. O or C Reason Code: 60. Si or N Reason Code: 61. Cl or Br Reason Code: 62. Be or Sr Reason Code: 63. Si or S Reason Code: 64. Na or Ca Reason Code: Reactivity: Which atom is each pair is more reactive? Choose the appropriate reason code. Reason Codes: A-It is trying to lose electrons & has more energy levels shielding the nucleus pull so it loses electrons easier B- It is trying to gain electrons and has fewer energy levels shielding the nucleus pull so it gains electrons easier C-It is trying to lose elctrons and has fewer protons in the nucleus making it easier to lose the electrons. D- It is trying to gain electrons and has more protons making it easier to attract electrons E- It does not complete the octet rule on its own so it gains or loses electrons or reacts to fulfill the octet rule. 65. Mg or Sr Reason Code: 66. Se or O Reason Code: 67. N or F Reason Code: 68. K or Fe Reason Code: 69. Kr or Si Reason Code: 70. Sr or Be Reason Code: 71. I or Cl Reason Code: 72. Mo or Ag Reason Code:
IONIC BONDING 73. How many valence electrons does Phosphorus have? 74. Does Phosphorus want to gain or lose electrons? 75. What will be the charge on the Phosphorus ion? 76. How many valence electrons does Magnesium have? 77. Does Magnesium want to gain or lose electrons? 78. What will be the charge on the Magnesium ion? 79. What will be the ratio of Magnesium atoms to Phosphorus atoms be for a compound to form? 80. What will be the formula for this compound? 81. What will be the name for this compound? 82. How many valence electrons does Lithium have? 83. Does Lithium want to gain or lose electrons? 84. What will be the charge on the Lithium ion? 85. How many valence electrons does Oxygen have? 86. Does Oxygen want to gain or lose electrons? 87. What will be the charge on the Oxygen ion? 88. What will be the ratio of Lithium atoms to Oxygen atoms be for a compound to form? 89. What will be the formula for this compound? 90. What will be the name for this compound? 91. How many valence electrons does Aluminum have? 92. Does Aluminum want to gain or lose electrons? 93. What will be the charge on the Aluminum ion? 94. How many valence electrons does Sulfur have? 95. Does Sulfur want to gain or lose electrons? 96. What will be the charge on the Sulfur ion?
97. What will be the ratio of Aluminum atoms to Sulfur atoms be for a compound to form? 98. What will be the formula for this compound? 99. What will be the name for this compound? 100. How many valence electrons does Potassium have? 101. Does Potassium want to gain or lose electrons? 102. What will be the charge on the Potassium ion? 103. How many valence electrons does Chlorine have? 104. Does Chlorine want to gain or lose electrons? 105. What will be the charge on the Chlorine ion? 106. What will be the ratio of Potassium atoms to Chlorine atoms be for a compound to form? 107. What will be the formula for this compound? 108. What will be the name for this compound? PHYSICAL OR CHEMICAL??? List whether the following changes are physical or chemical (P or C). 109. Dry ice sublimes, or goes directly from a solid to a gas, in a Halloween special effect! 110. Vinegar and baking soda react to form carbon dioxide bubbles in a homemade volcano. 111. Alcohol evaporates on your skin as the doctor cleans your arm for a shot. 112. A candy bar is digested in your body when you eat it. 113. A bicycle left in the rain begins to rust after several days. 114. Kool-aid crystals are added to water and dissolve when drinks are made for a party. 115. Water turns into invisible steam bubbles when a pot of water is boiled for spaghetti. 116. Sulfuric acid in a car battery eats through the engine of a car when it leaks. 117. A piece of paper is burned in order to start a campfire.
ELEMENT, COMPOUND, OR MIXTURE??? List whether the following substances are elements, compounds, or mixtures (E, C, M). If it is a mixture, indicate if it is a heterogeneous mixture (HEM), or a homogeneous mixture (HOM - also known as a solution). 118. Mouthwash 119. Salad 120. Table Sugar 121. Aluminum Foil 122. Steel Bike 123. Tap Water 124. Air 125. Ocean Water 126. Chocolate Chip Cookie 127. Copper wire 128. Table Salt 129. Distilled Water For the following situation, list whether each step is a physical change (P) or a chemical change (C). Someone had started a fire at an apartment complex with some gasoline. They lit a match and it ignited the gasoline. The fire was so hot, that some of the paint on a nearby car began to melt. When the firefighters arrived, they began pouring water on the fire. The water could not contain the intense heat, as the water began to boil as soon as it hit the fire. Because a nearby factory contained explosive fireworks, the hazardous materials unit was called in. The fireworks began to explode violently. They were able to contain the fire by dropping a chemical known as calcium carbonate on the building from an airplane. The calcium carbonate chemically decomposed into carbon dioxide gas, which then put out the fire.