1. Topic: Nuclear Chemistry
Aim: How do you distinguish natural and artificial transmutations?
Do Now: Complete the decay equation.
239Pu  _____ + _____
(Hint: Use Tables N & O, the Per. Table, & your notes from Monday)
HW: Text p. 879 #1-3, 5, 7, 8
p. 886 #14

2. Transmutations
Natural: types we already studied (wrote equations for these) – nucleus spontaneously decays to form a new element
Table N radioisotopes all decay naturally (spontaneously)
Give off alpha beta, or positron particles
Artificial: transforming 1 element into another by bombarding the nucleus with high-energy particles
Particle accelerators speed up the particles enough to cause an artificial transmutation
How man-made elements are produced

3. Artificial Transmutations
Nitrogen nucleus bombards Californium nucleus
4 neutrons given off – forms element Dubnium
New element (Dubnium) is synthetic

4. Artificial Transmutations
Tell me what’s happening in this reaction
Use words like “bombard”, “emit”, etc.

5. How to ID Natural vs. Artificial Transmutations
Artificial transmutations MUST HAVE 2 REACTANTS, whereas natural transmutations have ONLY 1 REACTANT B/C THE ELEMENT DECAYS SPONTANEOUSLY
Review book p. 221 #16-23

6. Practical Applications – Artificial Transmutation
Nuclear Energy
Mass is converted into energy
Energy yield is approx. 1 billion times the energy released when the same amt of a fossil fuel is burned!

7. Nuclear Fission
Fission: nucleus of one atom splits into 2 or more pieces
Hint: Fission has an “i”, so does “splits”
Basic process:
Nucleus is bombarded with a high-speed neutron
Nucleus splits & gives off energy
Lighter nuclei formed are more stable than the parent nucleus, but are often radioactive themselves.
FISSION simple animation 7

8. Fission Chain Reaction
Example: Uranium
Neutrons given off as products can bombard other uranium nuclei, causing them to split as well – etc.
In a controlled setting, this is a nuclear reactor that can be used for energy
(java)
In an uncontrolled setting, this is atomic bomb – Manhattan Project

9. Nuclear Fusion Fusion: 2 light nuclei unite to form a heavier nucleus
Hint: fusion has a “u”, so does unite
Hydrogen bomb
Fusion Reactor
Proton-Proton chain in stars

10. Nuclei unite – more energy
Fission & Fusion
High energy requirements
High temperature is necessary – why?
High pressure is necessary – why?
Fission
Fusion
Similar
Rxns produce energy
Different
Nucleus splits
Nuclei unite – more energy

11. Sample Questions
Review book p. 223 #24-33