1. Unit 4
Nuclear Reactions

2. What happens when you shoot the cue ball into an area of densely packed pool balls?
* they spread apart
 you “BREAK” the pack

3. Nuclear Fission
The splitting of a nucleus into two (2) nuclei with smaller masses.
* “fission” means to divide

4. Only large nuclei with atomic numbers above 90 can undergo nuclear fission.

5. What happens in nuclear fission?
n + U  Ba + Kr + 3n
1 Uranium atom
1 neutron
1 Barium atom
1 Krypton atom
3 neutrons

6. MASSIVE
ENERGY
RELEASE

7. Chain Reaction An ongoing series of fission reactions * Domino effect
 a mouse trap setting off more mouse traps

8. Splitting 1 uranium nucleus produces several million times more energy than reacting 1 molecule of dynamite.

9. Nuclear Fusion
The combining of two nuclei with low masses to form one nucleus of greater mass.
* “fusion” means to put together

10. Nuclear fusion is difficult to induce because extremely HIGH temperatures are required.
* A.K.A. = thermonuclear reaction

11. Our Sun, and all stars, are fueled by nuclear fusion reactions.
* hydrogen atoms combine to create helium

12. Why do you think the Sun can go through nuclear fusion?
Extremely high temperatures in the Sun’s core.

13. Scientist are searching for a way to induce and control nuclear fusion.
* WHY?
 unlimited supply of energy for electricity

14. THE END