Nuclear Chemistry Chapter 4: Discovering the Secrets of the Nucleus From a Photographic Mystery to the Atomic Bomb Nuclear Energy, Nuclear Medicine, and a Nuclear Calendar Chapter 5: Harnessing the Secrets of the Nucleus www.grossmont.edu/.../powerpoint%20lectures/ch%204& ...

TEKS 12 (A) describe the characteristics of alpha, beta, and gamma radiation; 12 (B) describe radioactive decay process in terms of balanced nuclear equations; and 12 (C) compare fission and fusion reactions.

© 2003 John Wiley and Sons Publishers Figure 4.1

Antoine Henri Becquierel. © 2003 John Wiley and Sons Publishers Antoine Henri Becquierel. In 1903 he shared a Nobel Prize with Marie and Pierre Curie for the discovery of radioactivity. Courtesy Culver Pictures, Inc. Antoine Henri Becquierel.

Radioactive Decay Discovered by Antoine Henri Becquerel in 1896 He saw that photographic plates developed bright spots when exposed to uranium metals

Types of nuclear reactions Radioactive Decay – nucleus decays spontaneously giving off an energetic particle Nuclear Bombardment – shoot a high energy particle at the nucleus of another atom and watch what happens

Writing Nuclear Equations

Figure 4.4: The components of α rays, β rays, and γ rays. © 2003 John Wiley and Sons Publishers Figure 4.4: The components of α rays, β rays, and γ rays.

Figure 4.2: The penetrating power of radiation. © 2003 John Wiley and Sons Publishers Figure 4.2: The penetrating power of radiation.

Figure 5.3: Ionizing power and penetrating power: an analogy. © 2003 John Wiley and Sons Publishers Figure 5.3: Ionizing power and penetrating power: an analogy. The truck represents a B particle, and the motor bike represents a y ray. Figure 5.3: Ionizing power and penetrating power: an analogy.

Types of radioactive decay alpha particle emission beta emission positron emission electron capture gamma emission

Types of radioactive decay alpha particle emission loss of a helium nucleus.

Problem Pu-239 (plutonium 239) loses an alpha particle (He nucleus) Problem Pu-239 (plutonium 239) loses an alpha particle (He nucleus). Write the nuclear reaction

Types of radioactive decay beta emission A neutron splits into a proton and electron which is spit out as a b particle.

b particle emission

Types of radioactive decay positron emission A proton kicks out positive charge (a positron, b+) to become a neutron. The positron collides with an electron annihilating both and generating energy

Types of radioactive decay electron capture (EC) an electron (from inner shell) is sucked into the nucleus to combine with a proton – produces a neutron. gamma emission emission of energy (photon) from an unstable nucleus.

© 2003 John Wiley and Sons Publishers QUESTION © 2003 John Wiley and Sons Publishers How does an atom’s atomic number change when its nucleus loses a(n): (a) α particle, (b) β particle, (c)  ray? How does that atom’s mass number change with the loss of each of these? Page 64

Pu-239 (plutonium 239) loses an alpha particle (He nucleus) Pu-239 (plutonium 239) loses an alpha particle (He nucleus). Write the nuclear reaction.

Nuclear Bombardment Reactions Transmutation – changing one element to another by shooting a nuclear particle at its nucleus. All transuranium elements (more than 92 protons) were created synthetically in particle accelerators.

Transmutation Reaction

Figure 4.8: A typical fission reaction of U-235. © 2003 John Wiley and Sons Publishers Figure 4.8: A typical fission reaction of U-235.

© 2003 John Wiley and Sons Publishers Courtesy Shigeo Hayashi Remains of a building after the explosion of the uranium bomb at Hiroshima, August 6, 1945.

Figure 5.1: Schematic diagram of a nuclear power plant. © 2003 John Wiley and Sons Publishers Figure 5.1: Schematic diagram of a nuclear power plant.