1. Electromagnetic Radiation
-is a form of energy and has no mass
- travels at the speed of light
- travels in bundles called “photons”
- can travel through a vacuum
- is emitted by atoms in nuclear decay, or after atoms are energized by heating
(tungsten or firework fuse)
- has wave like properties
- high energy radiation has high frequency
and short wave length.

3. What is Ionizing Radiation?
Introduction to
Radioactivity

5. Is ionizing radiation a problem?
Ionization of molecules and excitations can:
Produce free radicals.
Break chemical bonds.
Produce new chemical bonds and cross-linkage between macromolecules.
Damage molecules that regulate vital cell processes (e.g. DNA, RNA, proteins).

6. The problem is proportional to exposure; the cell can repair certain levels of cell damage.
At low doses, such as that received every day from background radiation, cellular damage is rapidly repaired. 
At higher levels, cell death results.
At extremely high doses, cells cannot be replaced quickly enough, and tissues fail to function.

7. Key Differences Non-Ionizing radiation
- has much lower energy than ionizing
- includes visible and lower regions of EM Spectrum
- causes electrons to move to higher energy levels
- can cause chemical reactions to occur (microwaves)
- transmits radio and phone signals
- dangerous when it causes a sun burn, or microwave burn
Ionizing radiation
- dangerous due to high frequency and high energy
- cannot see it, smell it, feel it or sense it.
- ultraviolet, X-rays, cosmic rays and gamma rays
- causes ions to form when electrons are ejected from nuclei
- dangerous damage to living systems from ions
- U.V. light damaged skin causes skin cancer
- Biological effects studied for nearly 70 years

9. Kinds of Radiation Electromagnetic radiation: Decay Particles
Ultra High frequency Cosmic rays
Gamma rays
X-rays
Ultra violet B rays- Bad for us
Ultraviolet A rays- cause tanning (above purple)
Visible light
Infra red ( Below red)
Decay Particles
Alpha (He nuclei)
Beta (electron like particle from nucleus)
Gamma ray
Fission particles
Neutrons

13. Medical Imaging and the EM Spectrum

16. Transmutation is when one element decays by emitting a particle from the nucleus. This causes a change in the number of protons and neutrons in the nucleus.
Over a long period of time the atom changes into another type of element. This process is called trans – meaning across mutation – meaning change or change across the periodic table. One element decays into another element! The process continues until a stable of non-changing element is produced!

17. Radiation Exposure
Whether you are exposed externally (outside the body) or internally (inside the body) both are considered significant when analyzing exposure.

19. The longer your exposure
Time
The longer your exposure
The greater your dose
The greater the danger!

28. Radiation Dosimetry