Nuclear Fission and Fusion

Essential Questions What is the difference between fission and fusion? How does a nuclear power plant work? I know one is used in the sun and one is used in a nuclear power plant, which one is which and what’s the difference?

BBC video about fission and fusion Fission vs Fusion BBC video about fission and fusion http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/fission_fusion/fissionfusionact.shtml

Nuclear Fission In nuclear fission, a large nucleus is bombarded with a small particle. the nucleus splits into smaller nuclei and several neutrons. large amounts of energy are released.

Nuclear Fission When a neutron bombards 235U, an unstable nucleus of 236U undergoes fission (splits). smaller nuclei are produced such as Kr-91 and Ba-142. neutrons are released to bombard more 235U. 1n + 235U “236U” 91Kr + 142Ba + 3 1n + 0 92 92 36 56 0 Energy

Nuclear Fission Diagram 1n + 235U “236U” 91Kr + 142Ba + 3 1n + energy 0 92 92 36 56 0

Check for understanding Supply the missing atomic symbol to complete the equation for the following nuclear fission reaction. 1n + 235U 137Te + ?X + 2 1n + energy 0 92 52 ? 0 Calculate the mass number on each side Calculate the atomic number on each side Figure out the missing element

Solution 1n + 235U 137Te + 97Zr + 2 1n + energy 0 92 52 40 0

U + Ba n 3 Kr U + Cs n 2 Rb Practice with fission 235 92 141 56 1 36 3 Kr 36 U 235 92 + Cs 138 55 n 1 2 Rb 96 37

Chain Reaction A chain reaction occurs when a critical mass of uranium undergoes repeated fission, releasing a large amount of heat and energy that produces an atomic explosion.

Nuclear Power Plants In nuclear power plants, fission is used to produce energy. control rods in the reactor absorb neutrons to slow and control the chain reactions of fission.

Nuclear Power Plants How do nuclear power plants work? http://www.youtube.com/watch?v=VJfIbBDR3e8

Nuclear Fusion Fusion occurs at extremely high temperatures (100 000 000°C). combines or fuses small nuclei into larger nuclei. releases large amounts of energy. occurs continuously in the sun and stars.

Fusion: small nuclei form larger nuclide, release energy This type of Fusion is being examined as An alternative Energy source On Earth. Small nuclei come together to form larger nuclide, releasing energy

Check for understanding Indicate if each of the following describes 1) nuclear fission or 2) nuclear fusion 3) both ___ A. a nucleus splits. ___ B. large amounts of energy are released. ___ C. small nuclei form larger nuclei. ___ D. hydrogen nuclei react to form new elements. ___ E. several neutrons are released.

Solution Indicate if each of the following is 1) nuclear fission or 2) nuclear fusion. 1 A. a nucleus splits. 3 B. large amounts of energy are released. 2 C. small nuclei form larger nuclei. 2 D. hydrogen nuclei react. 3 E. several neutrons are released.

Stop: Work on Nuclear Fission and Fusion POGIL with a partner

The Elements: Forged in the Stars Nova video http://www.youtube.com/watch?v=uKqvjEE0wFg

Review for Quiz Jeopardy http://www.superteachertools.com/jeopardyx/jeopardy-review-game-convert.php?gamefile=../jeopardy/usergames/Jun201024/jeopardy1276622912.txt