Final Exam Sample Questions (Ch ) Nuclear Energy, the Periodic Table, and Chemistry

Transcription

1 Final Exam Sample Questions (Ch ) Nuclear Energy, the Periodic Table, and Chemistry 1. What causes the chain reaction in a uranium-based nuclear power plant? (a) Human operators who constantly pump additional power into the nuclear core (b) The presence of water needed for cooling in the center of the nuclear core (c) The release of extra neutrons when uranium atoms break apart (d) The gamma radiation produced by the radioactive waste (e) The beta radiation produced by the radioactive waste 2. This type of radiation occurs as relatively massive, positively charged particles leaving the nucleus. (a) (alpha rays) (b) (beta rays) (c) (gamma rays) 3. This type of radiation is that are created and then immediately expelled from the nucleus when a neutron spontaneously turns into a proton. (a) (alpha rays) (b) (beta rays) (c) (gamma rays) 4. This type of radiation consists of high frequency photons. It is also the most dangerous of the three type of radiation. (a) (alpha rays) (b) (beta rays) (c) (gamma rays) 5. Where does the energy in a nuclear reactor that produces electricity from heat come from? (a) Mass is lost when uranium atoms break apart; this lost mass shows up as kinetic energy which becomes heat (b) The burning, i.e., oxidation, of uranium much like the burning of wood or coal, except uranium burns much hotter (c) Chemical reactions when several uranium atoms bond together to form a solid; the chemical reactions are the type that give off heat (d) The alpha, beta, and gamma radiation that occurs with all uranium atoms (e) The gamma radiation that occurs with all uranium atoms 6. Which is (are) legitimate concern(s) related to nuclear power plants that create electricity for societal use? I. An accidental nuclear explosion could occur in the vicinity of residential areas II. A malfunction could result in the reactor core getting too hot, resulting in a meltdown and leakage of radioactive material from the core III. The uncertainty on what to do with leftover radioactive waste material from the reactor core (a) I only (b) II only (c) III only (d) II and III only (e) I, II, and III 7. Why is a nuclear explosion at a uranium nuclear power plant virtually impossible? (a) The amount of uranium is less than the critical mass (b) The plant supervisors are very vigilant because their lives are on the line (c) There are several levels of inspections - private, state, and federal (d) The uranium fuel is not sufficiently enriched in U relative to U (e) The question is misleading since a nuclear explosion has occurred at least once at a nuclear power plant

2 8. When control rods are inserted into a nuclear reactor core, they _. (a) have no effect on the production of heat from the nuclear process (b) slow down the production of heat in the nuclear reaction (c) speed up the production of heat in the nuclear reaction 9. How does Einstein s famous equation, E=mc 2 (also written as E= mc 2 ), relate to energy generated in a nuclear reaction involving the breakup of uranium atoms? (a) It describes what happens when uranium is placed near material that is decaying via alpharadiation. (b) It describes what happens when uranium is placed near material that is decaying via betaradiation. (c) It describes what happens when uranium is placed near material that is decaying via gammaradiation. (d) It explains how the burning, i.e., oxidation, of uranium much like the burning of wood or coal, can give off significant amounts of energy. (e) It indicates that a large gain in energy results from a small loss in mass since the lost mass is multiplied by a very large number. 10. A(n) is one of the elements of the Periodic Table that has a given atomic number. (a) atom (b) nucleus (c) group (d) compound (e) mixture 11. A _ is when different materials are interspersed with each other without chemically bonding, like lettuce and tomatoes in a salad. (a) compound (b) mixture (c) group (d) system (e) period 12. An example of an allotrope is: (a) The formation of carbon into graphite, diamond, and bucky balls (b) The ionic bond formed when elements from the 2A group bond with those from the 6A (c) The formation of N 2 when individual nitrogen atoms bond with each other (d) When a substance such as dry ice vaporizes without becoming a liquid first (e) The covalent bond formed when non-metals bonds 13. An 18-karat gold ring: (a) Is 18% gold (b) Is 50% gold (c) Is 75% gold (d) Has 3 g of gold (e) Has 18 g of gold 14. A 6-karat diamond: (a) Is less than 6% pure diamond (b) Is exactly 6% pure diamond (c) Has a mass which is less than 1 g (d) Has a mass which is a little more than 1 g (e) Has a mass of 6 g

3 15. The representative elements are found: (a) Only among the very heavy elements (b) Only on the left side of the Periodic Table (c) In the middle columns of the Periodic Table (d) Only in the last column on the right side of the Periodic Table (e) On both the right and left sides of the Periodic Table 16. The transition elements are found: (a) Only among the very heavy elements (b) Only on the left side of the Periodic Table (c) In the middle columns of the Periodic Table (d) Only in the last column on the right side of the Periodic Table (e) On both the right and left sides of the Periodic Table 17. Elements that have their outer shell fill to capacity are found: (a) In the first column of the Periodic Table (b) In the second column of the Periodic Table (c) In the second to last column of the Periodic Table (d) In the last column of the Periodic Table (e) Throughout the Periodic Table, irrespective of which column they are in 18. A(n) is a complete row in the Periodic Table, while a(n) _ is a column in the Periodic Table. (a) period, group (b) group, period (c) section, system (d) system, section (e) prototype, allotrope 19. Which statement correctly summarizes the distinction between metals and non-metals among the elements in groups 1A-8A? (a) Metals tend to accept one or more, while non-metals tend to give up one or more (b) Metals do not give up or accept more, while non-metals tend to accept one or more (c) Metals tend to give up one or more, while non-metals do not give up or accept more (d) Metals tend to accept one or more, while non-metals do not give up or accept more (e) Metals tend to give up one or more, while non-metals tend to accept one or more 20. The octet rule refers to: (a) A popular musical group in the 1960 s comprised of four female and four male performers (b) The tendency of elements to gain or lose so that their outer valence shell has exactly 8. (c) The tendency of all elements to undergo spontaneous nuclear decay until they become atoms of exactly 8 protons and 8 (d) The idea that an element can become ionized, but never to the extent of having 8 extra (e) The idea that an element can become ionized, but never to the extent of having a deficit of 8

4 21. Which contains elements that are all inert, i.e., non-reactive, and also belong to the noble gasses? (a) Cu, Ag, Au (b) F, Cl, Br (c) Ne, Ar, Kr (d) Li, Na, K (e) Fe, Co, Ni 22. Which is correct about a magnesium (Mg) atom? (a) Its outer shell will be filled if it gains two (b) Its outer shell will be filled if it gains one electron (c) Its outer shell will be filled if it loses one electron (d) Its outer shell will be filled if it loses two (e) Its outer shell is filled as is 23. Which contains elements that have outer shells with one electron? Assume they are not positively or negatively ionized when answering. (a) O, S, Se (b) Mg, Ca, Sr (c) P, S, Cl (d) F, Cl, Br (e) Na, K, Rb 24. Which contains elements that could readily become -3 ions? (a) Mg, Ca, Sr (b) Al, Ga, In (c) O, S, Se (d) N, P, As (e) F, Cl, Br 25. Which molecule is formed by ionic bonding? (a) KBr (b) FCl (c) SiO 2 (d) CO 2 (e) CBr N 2 forms a _ bond because. (a) metallic; it can act like a metal when not around other elements (b) ionic; the two nitrogen atoms share so both have eight in the valence shell (c) covalent; the two nitrogen atoms share so both have eight in the valence shell (d) ionic; one of the nitrogen atoms gains an electron and the other loses an electron (e) covalent; one of the nitrogen atoms gains an electron and the other loses an electron 27. Which is correct about the molecule formed when atoms of Ca and Cl bond? (a) It is CaCl formed by covalent bonding (b) It is CaCl 2 formed by covalent bonding (c) It is Ca 2Cl formed by covalent bonding (d) It is CaCl 2 formed by ionic bonding (e) It is Ca 2Cl formed by ionic bonding For Questions 28-29, use the following diagram that shows the energetics of a chemical reaction as discussed in class. Energy Reactants Products A B C

5 28. The reaction shown in the diagram: (a) Is exothermic (b) Is endothermic (c) Is neither exothermic nor endothermic (d) Is half exothermic and half endothermic (e) Could be either exothermic or endothermic (there is insufficient information to distinguish between the two) 29. If a catalyst were used in this reaction, the catalyst could speed up the reaction by: (a) Raising the energy level of the reactants in section A (b) Lowering the energy level of the products in section C (c) Raising the energy level of the products in section C (d) Lowering the level of the energy bump in section B (e) Raising the level of the energy bump in section B 30. Which statement correctly summarizes the energetics of the chemical reaction that occurs when someone strikes a match on the rough section of the matchbox to start it burning and then holds it for a few seconds while it burns? (a) The reaction is endothermic and does not require a catalyst to get started (b) The reaction is endothermic and requires a catalyst to get started (c) The reaction is exothermic and does not require a catalyst or activation energy to get started (d) The reaction is exothermic and requires a catalyst to get started (e) The reaction is exothermic and requires an activation energy to get started 31. When NH 3 is added to water, it breaks down into NH 4 + and OH - ions as indicated by the following chemical formula: NH 3 + H 2O NH OH - We say that NH 3 is a(n) because _. (a) base; positive ions are formed (b) base; OH - ions are formed (c) acid; positive ions are formed (d) acid; OH - ions are formed (e) acid; both positive and negative ions are formed when water is added 32. When HCl is added to water, it breaks down into H 30 + and Cl - ions as indicated by the chemical formula: HCl + H 2O H Cl - We say that HCl is a(n) because _. (a) base; Cl - ions are formed (b) base; both positive and negative ions are formed (c) acid; H 30 + ions are formed (d) acid; Cl - ions are formed (e) acid; both positive and negative ions are formed when water is added

6 Fill in the blanks for each of the follow nuclear reaction or decay processes Pa Type (,, or ): _ e n Th + 2 He n Type (,, or ): O Ne 6 C + ++ n Th F He n ++ r