<p> 8th Grade Physical Science-Unit 2 study guide</p><p>Vocabulary</p><p>Protons</p><p>Neutrons</p><p>Electrons</p><p>Nucleus</p><p>Matter</p><p>Atom</p><p>Atomic number</p><p>Atomic mass</p><p>Mass Number</p><p>Ion</p><p>Isotope</p><p>Compound</p><p>Element</p><p>Heterogeneous mixture</p><p>Homogeneous mixture</p><p>Ionic bond</p><p>Covalent Bond Practice questions</p><p>1. What kind of charge does the nucleus have?</p><p>The nucleus has a positive charge because it contains the protons (+) and the neutrons (no charge)</p><p>2. Where is most of the atoms mass located?</p><p>A majority of the mass is located in the nucleus where the protons and neutrons are found. The protons and neutron are much larger than the electrons</p><p>3. What is the law of conservations of matter?</p><p>Matter cannot be created or be destroyed.</p><p>4. As fuel is burned in an airplane, it seems to disappear from the tank, suggesting that matter is destroyed during the reaction. Explain why this is not true</p><p>According to the law of conservation of matter, it cannot be created nor destroyed. In this example, the gas is merely changing states from a liquid to a gas.</p><p>5. Draw and label a carbon atom including; protons, neutrons and electrons. 6. How many protons does the atom have? 6</p><p>7. How many neutrons does the atom have? 6</p><p>8. How many electrons does the atom have? 6</p><p>9. What is the atomic number of the atom? 6</p><p>10. What is the mass number of the atom? 12</p><p>11. What is the number of valence electrons? 4</p><p>12. An atom with a neutral charge contains an equal number of ____Protons and Electrons______.</p><p>13. The mass of the nucleus contains which two particles? Protons and neutrons </p><p>14. The following appears in a chemical equation:</p><p>2CO2 How many carbon atoms?____2_____</p><p>How many oxygen atoms?__4_____</p><p>15. Glucose (C6H12O6) is a kind of sugar molecule. How many total atoms are in a molecule of glucose? 24</p><p>16. Which elements would you predict to have the most similar physical and chemical properties to Calcium? Atoms located in group 2 of the periodic table.</p><p>17. What number is most important in determining how an atom will bond? Valence electrons</p><p>18. What elements are most likely to form a compound with elements in row 2? Elements from group 16</p><p>19. Which group of elements has a full outer energy level containing eight electrons? Group 18, noble gases</p><p>20. What is helium’s atomic number? 18 </p><p>21. What is helium’s symbol? ___He______</p><p>22. What is helium’s atomic mass? ___4.003____</p><p>23. How many of the following subatomic particles does helium have? </p><p>Protons____2__ Neutrons___2______Electrons___2______</p><p>24. Carbon has two three isotopes Carbon-12 and carbon-13 and carbon-14. For each of the isotopes, complete the chart below. (10 points)</p><p>Isotope Name Atomic Mass Number of Number of Number of number number Protons Neutrons electrons Carbon-12 6 12 6 6 6 Carbon-13 6 13 6 7 6 Carbon-14 6 14 6 8 6</p><p>25. Complete the chart using the periodic table provided to help you</p><p>Atomic Total number of Number of Number of Oxidation Element Symbol electrons valence electrons electrons lost or Number gain Iodine I 53 7 +(-1) -1 Lead Pb 82 4 +/- (-4) +/1 (-4) Strontium Sr 38 2 - (-2) 2 Hydrogen H 1 1 +/1 (-1) +/- 1</p>