1. Radiation

2. Radiation
When you see or hear this word what do you think about? What do you think it means?
Share your thoughts with me by writing on the post it what you think about when you see this word. Do not put your name on the post it.

3. Radiation is all around us
It comes from the Earth and from outer space.
Many forms of radiation are invisible -- we can't feel it, see it, taste it, or smell it.
Yet, it can be detected and measured when present.

4. Everyday we are exposed to Radiation
Called natural or background radiation.
Natural radiation accounts for about half of our total annual exposure.
Man-made sources — mostly medical procedures make up the other 50%.

5. Natural or Background Radiation
Radon, a radioactive gas from uranium found in soil dispersed in the air; Today Show - Radon Gas
Radioactive Potassium in our food and water;
Uranium, Radium, and Thorium in the Earth's crust;
And from Cosmic Rays and the Sun.

6. Man-made radiation sources
tobacco,
television,
medical x-rays,
smoke detectors,
lantern mantles,
nuclear medicine,
and building materials.
Click Image to calculate your radiation exposure according to the American Nuclear Society.

7. Radiation Damage Mutate hemoglobin Mutate cells, lose function
Destroy immune system
Burn skin, destroy bone

8. Radioactive Tracer What is a radioactive tracer?
- short lived isotope that can be observed with a sensitive detector

9. Radioactive Tracer How are they used?
- Agriculture – measure water flow
- Medicine – locate tumors
- Medical research – trace drug paths thru body
- Geology – trace underground water flow

10. Radioisotope tracers in Medicine

11. Measuring Radiation
A Geiger counter has a negatively charged Cu tube with a positively charged wire running through it.

12. Measuring Radiation The tube is filled with gas at low pressure.
Radiation knocks electrons off the gas which are attracted to the wire producing a current.

13. Measuring Radiation
An amplifier strengthens the current producing a clicking sound or a flashing light.
The number of clicks or flashes per second tell how strong the radiation is.

14. Watch and Learn Everyday Radiation Clip Radon Radiation
Facts About Radiation
Interactive Sources of Radiation
Show Geiger Counter Demos
“Whys Guy” shows some everyday radioactive materials. 4:24 min
Fiesta Ware Info

15. But what is radiation?
Radioactive materials are composed of atoms that are unstable.
An unstable atom gives off its excess energy until it becomes stable.
The energy emitted
is radiation.

16. Know this…
While there are several different forms of radiation, we're going to concentrate on just three that result from the decay of radioactive isotopes:
alpha,
beta,
gamma.

17. Let’s Review What You Already Know
What are isotopes?
Element that have the same number of protons, but a different number of neutrons. Chemist call isotopes Nuclide
What are radioactive isotopes?
Isotopes that are radioactive.

18. Let’s Review A radioactive isotope emits particles and energy.
When the process occurs, the radioactive isotope goes through nuclear decay producing…
An entirely new element or
Another isotope of same element

19. Nuclear Radiation
Nuclear radiation = matter and energy released when a radioactive isotope decays

20. What happens when an element undergoes radioactive decay?
During radioactive decay an unstable nuclei of an isotope emits particles and releases energy, to become a stable isotope.
“NUCLEAR”
To radiate means “to give off”

21. Non – Ionizing Radiation
Radiation that has enough energy to move atoms in a molecule around or cause them to vibrate, but not enough to move electrons.
We take advantage of the properties of non-ionizing radiation for common tasks:
microwave radiation– telecommunications and heating food
infrared radiation --infrared lamps to keep food warm in restaurants
radio waves-- broadcasting
My electrons vibrate!

22. Electromagnetic Radiation
Energy given off by an atom due to an acceleration of the atoms electrons

23. Ionizing Radiation
Radiation that falls within the ionizing radiation" range has enough energy to remove tightly bound electrons from atoms, thus creating ions.
This is the type of radiation that people usually think of as 'radiation.'
We take advantage of its properties to generate electric power, to kill cancer cells, and in many manufacturing processes.
You make my electrons leave!

24. Nuclear Radiation
A release of energy and particles from the nucleus of an atom

25. The energy of the radiation shown on the spectrum below increases from left to right as the frequency rises.
Type of Radiation
Effects
Source

26. Three types of Ionizing Radiation
Alpha Particles
Beta Particles
Gamma Rays

27. Alpha Particles (think charged particle Helium)
What is it? Helium Nucleus
Energy – Low Energy
Speed – Varies
Range – 5 m (15ft.) in air, can be stopped by paper or skin
Shielding required – None
Biological Hazard – None unless in large quantities- Least Harmful
Atomic Changes
Mass number (decrease): -4 (2p +2n)
Atomic number: -2 (protons)

28. The “emission” of a helium nucleus – 2 protons and 2 neutrons

29. Alpha Decay

30. Alpha Decay

31. Beta Particle (think electron and transmutation)
What is it? High Speed Electron- A neutron splits into a proton and an electron
Energy – Varies
Speed – Varies
Range – 5 m in air, can be stopped by clothes or wood
Shielding required – moderate clothing
Biological Hazard – Superficial Skin injury
Atomic Changes
Mass number: no change
Atomic number: +1 (protons)

32. Beta Decay

33. Beta Decay

34. Beta Decay

35. A neutron in the nucleus of the atom becomes a proton and emits an electron. Note: a neutron is not made of a proton and an electron.

36. Gamma Rays (think wave or high energy light)
What is it? Electromagnetic Energy – High Energy Radiation- NOT MADE of MATTER
Energy – Varies
Speed – Travels at the speed of Light
Range – 500 m in air, can be stopped by lead or many feet of concrete
Shielding required – dense material such as concrete, steel plate, earth
Biological Hazard – Dangerous to living things
Atomic Changes
No change
A Gamma Ray (ˠ) is produced

37. Gamma Rays
No Atomic Changes

38. Gamma Rays

39. Don’t worry…unless your name is Bruce.

40. Review

41. Nuclear Radiation

43. Alpha, Beta, and Gamma. Which objects can travel through video. :58 min

44. Electromagnetic Spectrum

45. Let’s Practice

46. Let’s Practice

47. Let’s Practice

48. Let’s Practice

49. Let’s Practice

50. Challenge with a partner
Use Atomic notation like the problems from the previous slides and create an alpha decay with the nuclide (isotope) of your choice

51. Challenge with a partner
Use Atomic notation like the problems from the previous slides and create an beta decay with the nuclide (isotope) of your choice