1. Nuclear Chemistry Chapter 21B
West Valley High School
General Chemistry
Mr. Mata

2. Tsutomu Yamaguchi
Survived both Hiroshima & Nagasaki atomic bombs.

3. Standard 11a
Students know the differences between nuclear fission and nuclear fusion reactions.

4. Essential Question
What are the uses of nuclear fission and nuclear fusion reactions?

5. Nuclear Radiation Discoveries
Rontgen discovers x-rays (1895).
Henri Becquerel (1896) discovered that uranium salts fogged photo plates.
Marie & Pierre Curie isolated uranium atoms from pitchblende and discover elements radium and polonium (1898).
Rutherford isolates alpha & beta (1899).
Villard discovers gamma particles (1900).

6. Nuclear Radiation Discoveries
Rutherford discovers + nucleus (1911).
Rutherford conducts 1st transmutation (1919)
Rutherford isolates proton (1919).
Chadwick discovers neutron (1932).
Lise Meitner & Otto Hahn discover elements thorium & protactinium (1935).
Fermi achieves first fission reaction(1942).
First electricity from fission reaction (1951).

7. Chemical vs. Nuclear Reactions
Chemical Reaction Nuclear Reaction
Change in electrons change in nucleus
(stable e- config.) (nucleons = P & N)
Temp, Press, Conc Temp, Press, Conc
affect reactions. don’t affect reactions.
Energy released radioactive decay
(heat & light) (alpha, beta, gamma)
Can be neutralized. Can’t be neutralized.

8. Nuclear Fission and Fusion
Fission: Splitting nucleus into smaller parts.
Fusion: Two nuclei combine to produce a heavier nucleus . 9

9. Fission

10. Fission Produces a Chain Reaction

11. Nuclear Fission Enormous amounts of energy released.
1 kg of U-235 releases energy = 20,000 tons TNT!
Atomic bombs start uncontrolled chain reactions.
Heavy nucleus is split into smaller nuclei.
Converts mass into energy E = mc2
10n U [23692U] (unstable)
23692U Sr Xe n

12. Nuclear Fission Bombs
First used in atomic bombs dropped on Hiroshima & Nagasaki (August 1945).
Both 23994Pu and 23592U were used.
U-235 bomb dropped on Hiroshima.
Pu-239 bomb dropped on Nagasaki.
U.S. only country to ever use nuclear bombs against enemy in war.

13. Effects of Fission
Atomic bomb: energy released suddenly as heat, pressure, radiation, neutrons.
Nuclear reactor: energy released slowly in the form of heat and radiation.
Neutrons released which cause other materials to become radioactive.
fission products remain “hot” for centuries.

14. Peaceful Uses of Fission
Nuclear power plants to generate electricity.
Fuel rods (containing U) give off neutrons.
Controlled using control rods (Zr or graphite) to absorb neutrons.
Causes reaction to occur at steady rate.
Energy of reaction is absorbed by water (steam) which drives turbine to produce electricity.

15. Nuclear Fission Reactor

16. Nuclear Reactor Core
the fuel rods in core contain enriched (3%) U-235.
control rods can slip between the fuel rods to absorb neutrons.
Regulates rate of water being heated in core.

17. Atomic Bomb Assembly

18. Hydrogen Bomb Assembly

19. Processing Nuclear Fuel
Uranium ore -> uranium oxide
Uranium oxide -> uranium flouride (UF6)
UF6 (0.7% enriched U-235)
UF6 (3% enriched U-235) nuclear reactors.
UF6 (80% + U-235) nuclear weapons.

20. Nuclear Fusion Thermonuclear reaction:
Energy released from the sun
Fusion releases more energy than fission.
Fusion products not radioactive.
Takes place at very high temperatures—in excess of 40,000,000C.

21. Application of Fusion
Fusion reactions are used in hydrogen bombs (“H” bombs”).
More powerful than fission bombs.
H-bomb is triggered by a fission bomb.
Unsuccessful attempts have been made to harness fusion to produce controllable energy.

22. Nuclear Fusion Reaction

23. Chapter 21B SUTW Prompt
Describe how nuclear fission differs from nuclear fusion.
Complete a sentence paragraph using the SUTW paragraph format. Hilight using green, yellow, and pink.
Due Date: Monday, October 24, 2016 (start of class).