Page 69 - Radiochemistry and nuclear chemistry

CHAPTER 4

Unstable Nuclei and Radioactive Decay

Contents

4.1. Radioactive decay 58
4.2. Conservation laws 60
4.3. Alpha decay 61
4.3.1. Detection 61
4.3.2. Decay energy 61
4.4. Beta decay 63
4.4.1. Detection 63
4.4.2. The/]-decay process 63
4.4.3. The neutrino 64
4.4.4. Double beta decay 67
4.4.5. B--decay 67
4.4.6. Positron decay 68
4.4.7. Electron capture 68
4.4.8. Daughter recoil 69
4.5. Gamma emission and internal conversion 70
4.6. Spontaneous fission 72
4.7. Rare modes of decay 74
4.8. Decay schemes and isotope charts 74
4.9. Secondary processes in the atom 76
4.10. Closed decay energy cycles 78
4.11. Kinetics of simple radioactive decay 79
4.12. Mixed decay 82
4.13. Radioactive decay units 83
4.14. Branching decay 84
4.15. Successive radioactive decay 84
4.16. Radioisotope generators 89
4.17. Decay energy and half-life 90
4.18. The Heisenberg uncertainty principle 90
4.19. Exercises 91
4.20. Literature 93

4.1. Radioactive decay

Radioactive decay is a spontaneous nuclear transformation that has been shown to be
unaffected by pressure, temperature, chemical form, etc (except a few very special cases).
This insensitivity to extranuclear conditions allows us to characterize radioactive nuclei by
their decay period and their mode and energy of decay without regard to their physical or
chemical condition.

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