Chapter 24 - Chapter 24.1 a) 24 Nuclear Reactions and Their...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
24 Chapter Nuclear Reactions and Their Applications 24.1 a) Chemical reactions are accompanied by relatively small changes in energy while nuclear reactions are accompanied by relatively large changes in energy. b) Rates of chemical reactions are increased by increasing temperature while nuclear reactions are not affected by temperature. c) Both are increased by higher reactant concentrations. d) Higher reactant concentrations would increase the yield of both nuclear reactions and chemical reactions. 24.2 a) 95.02%. In any naturally occurring sample of an element or its compounds, the isotopes of each element are present in their particular, nearly fixed proportions. b) The atomic mass would be larger than 31.972070, since 32 S is the lightest isotope. 24.3 a) She found that the intensity of emitted radiation is directly proportional to the concentration of the element in the various samples, not to the nature of the compound in which the element occurs. b) She found that certain uranium minerals were more radioactive than pure uranium, which implied that they contained traces of one or more as yet unknown, highly radioactive elements. Pitchblende is the principal ore of uranium. 24.4 X A Z A = mass number (protons + neutrons) Z = number of protons (positive charge) X = symbol for the particle N = A - Z (number of neutrons) a) X A Z B 4 2 Y - - A Z + 4 2 He ; 2 fewer protons, 2 fewer neutrons b) X A Z B A 1 Y + Z + 0 1 - β ; 1 more proton, 1 less neutron c) X* A Z B X A Z + 0 0 γ ( X* A Z = energy rich state), no change in number of protons or neutrons. d) X A Z B 1 Y - A Z + 0 1 + β ; 1 less proton, 1 more neutron e) X A Z + 0 1 e - B 1 Y - A Z ; 1 less proton, 1 more neutron A different element is produced in all cases except (c). 24.5 The key factor that determines the stability of a nuclide is the ratio of the number of neutrons to the number of protons, the N /Z ratio. If the N / Z ratio is either too high or not high enough, the nuclide is unstable and decays. 3 2 He N / Z = 1/2 2 2 He N / Z = 0/2, more unstable. 24.6 Neutron-rich nuclides, with a high N / Z , undergo β decay. Neutron-poor nuclides, with a low N / Z , undergo positron decay or electron capture. 24.7 Both kinds of decay increase the number of neutrons and decrease the number of protons. Positron emission is more common than electron capture among lighter nuclei; electron capture becomes increasingly common as nuclear charge increases. For Z < 20, β + -emission is more common; for Z 80, e - -capture is more common. 24.8 a) 234 92 U B 4 2 He + 230 90 Th b) 232 93 Np + 0 1 - β B 232 92 U c) 12 7 N B 0 1 β + 12 6 C 203
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
24.9 a) 26 11 Na B 0 1 - β + 26 12 Mg b) 223 87 Fr B 0 1 - β + 223 88 Ra c) 212 83 Bi B 4 2 He + 208 81 Tl 24.10 a) 27 12 Mg B 0 1 - β + 27 13 Al b) 9 3 Li B 1 0 n + 8 3 Li c) 103 46 Pd + 0 1 - β B 103 45 Rh 24.11 a) 8 2 He B 0 1 - β + 1 0 n + 7 3 Li b) 218 84 Po B 4 2 He + 214 82 Pb c) 110 49 In + 0 1 - β B 110 48 Cd 24.12 a) 48 23 V B 48 22 Ti + 0 1 β b) 107 48 Cd + 0 1 - β B 107 47 Ag c) 210 86
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/21/2010 for the course CHEM 1A taught by Professor Kobiashi during the Spring '07 term at Ventura College.

Page1 / 22

Chapter 24 - Chapter 24.1 a) 24 Nuclear Reactions and Their...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online