1. Fission and Fusion

2. Nuclear Reactions Two types of nuclear reactions that release energy.  Fission  Fusion

3. Fission - Definition  The nucleus splits into two or more smaller (lighter) atoms.

4. Fission – How it works  An unstable nucleus is hit with a small particle (neutron) and splits, releasing a LOT of energy.

5. Fission – How it works  Neutrons are released, causing more atoms to split.  This causes a CHAIN REACTION.

6. Critical mass: The amount of material present in a fusion reaction to cause a continuous chain reaction.  If MORE than the critical mass is present, an explosion may occur. Fission – How it works

7. Supply the missing atomic symbol to complete the equation for the following nuclear fission reaction. Fission – Example Equations

8. Fission - Uses Nuclear power plants:  Fission is used to produce energy  Control rods in the reactor absorb neutrons to control the fission chain https://www.youtube.com/watch?v=MGj_aJz7cTs Hyperlink:

9. Fission - Uses Nuclear power plants:  Fission is used to produce energy  Control rods in the reactor absorb neutrons to control the fission chain https://www.youtube.com/watch?v=MGj_aJz7cTs Hyperlink:

10. Fission - Uses Atomic Bombs:  UNCONTROLLED fission is used to produce energy

11. Fusion - Definition Fusion Fusion - Combining two light nuclei to form a heavier, more stable nucleus. https://www.youtube.com/watch?v=uKqvjEE0wFg https://www.youtube.com/watch?v=h7vyKDcSTaE Hyperlinks:

12. Fusion – How it Works Two light nuclei combine to form a heavier, more stable nucleus.  Occurs at extremely high temperatures (100,000,000 K)  Releases large amounts of energy (much more than with fission)

13. Fusion - Example Equations

14. Fusion - Uses Sun and Stars:  Our sun and stars have continuous fusion reactions ongoing.

15. Fusion - Uses Hydrogen Bomb:  Fuses together two hydrogen atoms to form heavier helium atoms  Releases MUCH more energy than a fission bomb.

16. FISSION v. FUSION Fission  Large isotopes (e.g., U-238) hit by neutron and break into smaller atoms  Temp. 1000 K  Used in nuclear reactors Fusion  Two smaller atoms collide and form larger atoms (e.g., H+H  He + energy)  Temp. 100,000,000 K  Reaction in our sun and stars, the H-bomb

17. Check Indicate if each of the following describes 1) nuclear fission or 2) nuclear fusion ___ A. a nucleus splits ___ B. large amounts of energy are released ___ C. small nuclei form larger nuclei ___ D. hydrogen nuclei combine ___ E. several neutrons are released ___ F. used to generate electricity ___ G. is too hot/too much energy to use 1) 1) & 2) 2)