Electromagnetic Waves

1. Obey the formula : Speed = Frequency x Wavelength

2. Ultra-violet rays

2.1. Can be obtained from sunlight.

2.2. Produces suntan.

2.3. Kills bacteria

2.4. Used to check counterfeit notes.

2.5. Can be dangerous when exposed excessively

3. Visible light

3.1. Encompasses all the colours of the spectrum.

3.1.1. Red

3.1.2. Yellow

3.1.3. Orange

3.1.4. Green

3.1.5. Blue

3.1.6. Violet

3.1.7. Indigo

3.2. To allow living creatures to see.

4. Properties

4.1. Travel at the speed of light.

4.1.1. Session Rule 1

4.1.2. Session Rule 2

4.2. Obey laws of reflection and refraction.

4.3. Transfer energy from one place to another.

4.4. Are transverse waves.

5. Infra-red rays

5.1. Emitted by hot objects.

5.2. Used in infrared detectors that convert the infrared into a visible image.

5.3. Used in night vision technologies.

5.3.1. Image enhancement

5.3.2. Thermal imaging.

6. Lower frequencies.

7. Higher frequencies.

7.1. Can cause ionization of cells and tissues which knocks off electrons from atoms, producing ions and free radicals that can damage DNA, cells and tissues.

8. Can cause a heating effect on cells and tissues when absorbed.

9. Gamma rays

9.1. Emitted by the nucleus of the radioactive atoms.

9.2. Used to sterilize medical instruments.

9.3. Kill cancerous cells.

9.4. Highly energetic and can do considerable damage to living cells.

10. X - Rays

10.1. Produced by firing high speed electrons at a metal target.

10.1.1. Sub Idea 1

10.1.2. Sub Idea 2

10.2. Used to produce an image of bone structure.

10.3. Can be dangerous when exposed excessively as it can do considerable damage to living cells.

11. Microwaves

11.1. Produced by special electronic devices eg Klystron.

11.2. Used to heat food up by giving energy to the water molecules in the food and this in turn produces the heating effect.

11.3. Used for satellite communications.

12. Radiowaves

12.1. Produced by electrons oscillating in electrical circuits.

12.2. Used for TV and radio transmissions.