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Unit Review 1. Assume that a chemical reaction goes to completion. (All of the reactant is converted to product.) According to the Law of Conservation of Matter, the mass of the product should be the original mass of the reactant. a. greater than b. less than © equal to 2. Neutral atoms of Cl-35 and Cl-37 differ with respect to their number of (a) neutrons b. protons c. positrons d. electrons 3. Which pair must represent atoms of the same element? a. 3Xand 14x @) 12x and 12x c. 18x and 44x d. 2X and $x 16. Which of the following statements is a part of Dalton’s atomic theory? a. Atoms can be created or destroyed. b. During a chemical reaction, atoms cannot be separated, combined, or rearranged. c. All atoms of a given element are not identical. ©) Different atoms combine in simple whole- number ratios to form compounds. 17. Asample of element X contains 90 percent X-35 atoms, 8 percent X-37 atoms, and 2 percent X-38 atoms. The average isotopic mass is closest to a 38 b. 32 c« 37 Ce 35 18. Atoms of 0-16, 0-17, and O-18 have the same number of a. electrons, but a different number of protons b. protons, but a different number of electrons : protons, but a different number of neutrons . neutrons, but a different number of protons 19. 20. 21. 22. 23. 24. 25, What two particles account for most of the mass in the atom? a. neutrons and positrons protons and neutrons ¢. protons and electrons d. neutrons and electrons What is the neutron-to-proton ratio in a stable atom of carbon-12? a 2:1 b. 12:1 G, 22 @® i In small atoms with stable nuclei, the neutron-to- proton ratio is usually a. greater than 1.5:1 b. less than 1:1 << around 1:1 d. between 1:1 and 1.5:1 Which radioactive emanation has a charge of 2+? a. aneutron b. a beta particle c. agamma ray a an alpha particle Carbon-13 is less stable than carbon-12 because carbon-13 has a. less neutrons b. less protons & more neutrons d. more protons Which particle has the greatest mass? a. anelectron ©) analpha particle c. aneutron d. a beta particle Given the equation: X—> dHe + ?22Rn The nucleus represented by X is | *gRa b. 728Po c. 2EPo d. #8Ra 26. 27. 28. 29. 30. 31. 32. Given the equation: YC > GN+X What particle is represented by the letter X? (@ abeta particle b. aproton c. aneutron d. an alpha particle Which radioactive isotope is used in geological dating? a. technetium-99 b. jodine-131 Q uranium-238 |. cobalt-60 The radioactive isotope carbon-14 can be used for a. controlling fission reactions determining the age of a bone c. determining medical disorders d. controlling speeds of neutrons An isotope of which element may be used as a fuel in a fission reaction? a. lithium plutonium c. carbon d. hydrogen The course of a chemical reaction can be traced by using a ‘a.) radioisotope diatomic molecule c. polar molecule d. stable isotope Radioisotopes used for medical diagnosis must have C&D short half-lives and be quickly eliminated by the body b. long half-lives and be quickly eliminated by the body c. short half-lives and be slowly eliminated by the body d. long half-lives and be slowly eliminated by the body All of the following are beneficial applications of radioactivity except a. tracing the path of an element through a complex reaction b. using dental x-rays to diagnose the health of teeth and gums mutations in reproductive cells by radiation d. destroying tumor cells with radiation therapy | 29 Matt and Atomic Structure P 2 | 31 47, The data table at the right shows three isotopes of Isotope Mass of isotope Percent Natural neon. __|_ {atomic mass units) Abundance a. Interms of atomic particles, state one 2Ne 19.99 90.9% difference between these three isotopes of © ” P Ne 20.99 0.3% neon. 2Ne 21.99 8.8% ie has 10, “Ne has Il Ue hay 12: b. Based on the atomic masses and the natural abundances shown in the data table, show a correct numerical setyp for calculating the average atomic mass of neon. UAL TIAD tau) + 0,37,(20.59 dims) + BAT (UG4 ame) foo%, c. Based on natural abundances, the average atomic mass of neon is closest to which whole number? 20 Amu (fur b 4H. is Do.1P nm) 48. Octane is combusted with oxygen to produce carbon dioxide and water, as shown in this balanced chemical equation: 2CeHis + 2502 > 16CO2 + 18H20 If 40.0 g of octane is completely combusted with 140.0 g oxygen, what total mass of carbon dioxide and water will form? 1$0-0g of product focm for, fhe Chemital reathen of (80.0 4 yeathanls, 49. Write nuclear equations for the following reactions. a. The alpha decay of radium-226. Mp, Rn + ie b. The beta decay of cesium-144. _ "Gs > IY e+ ve c. The fission of uranium-235 and a neutron into 3 neutrons, an atom of krypton-92 and an atom of 2°71, In > 38 intake + Gz Ml 
