1. Nuclear Energy
Chapter 15

2. 15.1
Radioactivity

3. Remember:
Atoms are made of protons, neutrons, and electrons

4. They have a correct balance of protons and neutrons.
Most atoms are stable
They have a correct balance of protons and neutrons.

5. Other atoms are unstable
They have an “off-balance” number of protons and neutrons.

6. Atoms whose nuclei are unstable are said to be
radioactive

7. Eventually, these atoms breakdown.

8. The process is called “radioactivity”.

9. Radioactivity is not new. Radioactivity is not caused by man.

11. Radioactive decay in Earth’s interior heats the water for geysers

12. Radioactive decay in Earth’s interior heats the water for hot springs

13. Most of the radiation we encounter

14. Nuclear Technology - Pros
Medical X-rays & Anti Cancer Treatments

15. Nuclear Technology - Pros
Smoke detectors

16. Nuclear Technology - Pros
Nuclear Energy

17. Nuclear Technology - Cons
Nuclear Disaster

18. Nuclear Technology - Cons
Nuclear Weapons

19. Nuclear Technology - Cons
Nuclear Weapons

20. Nuclear Technology Demands Responsibility
Safeguard nuclear material
Safe, clean disposal
Protect the environment for future generations

21. It’s up to you to make the decisions for the future!

22. Alpha, Beta, and Gamma Rays
Chapter 15.2
Alpha, Beta, and Gamma Rays

23. Radioactive elements emit 3 different types of particlesα β
alpha γ
beta
gamma

24. Radioactive Particles
α particles are positively charged β particles are negatively charged γ particles are neutral

27. α particles are He nuclei

28. α particles are Helium nuclei

29. α particles Relatively low speed Eventually become HE
Easy to shield against
Can’t go through paper or clothing

30. β particles are electrons
Neutrons “decay”
Produce a proton and electron

31. β particles Faster than α particles Can penetrate paper and clothes
Can penetrate and damage skin
Can not penetrate denser material like aluminum

32. γ (gamma) rays are pure energy
Gamma rays have more energy than visible light, UV light or X-rays

33. γ (gamma) rays Can easily penetrate and damage living tissue
Can penetrate most materials – except lead

34. Let’s Compare Penetrating Power

35. γ (gamma) rays can help preserve food

36. Question
Pretend you are given three radioactive rocks.
One is an alpha emitter, one is a beta emitter and one is a gamma emitter and you know which is which.

37. Question
You can throw one away.
Of the other two, you must hold one in your hand and place one in your shirt pocket.

38. Question
What can you do to minimize your exposure?

39. Answer
Hold the alpha emitter in your hand.
The skin on your hand will shield you.

40. Answer
Put the beta emitter in your pocket.
The combined thickness of you skin and clothing should shield you from the beta emissions.

41. THROW AWAY THE GAMMA EMITTER!
Answer
THROW AWAY THE GAMMA EMITTER!
Because it would penetrate your body from any of these locations.

42. Answer
In a perfect world……
Distance yourself from all the rocks!.