1. Radiation

2. What Is Radiation? • Unlike Conduction or Convection, Radiation can take place in space that is essentially empty of matter. • It is the transfer of heat in the form of infrared waves or subatomic particles emitted by one body, transmitted through a medium or space, and absorbed by another body. • Radiation is grouped by ionizing or non-ionizing radiation.

3. Diagram showing radiation Heat lost, radiation

4. What are the factors that affect radiation and absorption? • Temperature The higher the temperature, the higher the rate of radiation. • Nature of the surface Dark and dull colour surface are both good absorber and radiator, but shiny, silvery or white colour surface are good reflector, but poor absorber and radiator.

5. Diagram showing Nature of the surface affect the rate of radiation is used Heat from the Sun Solar panel having dark colour to absorb heat quickly from the Sun as black is a good absorber of heat

6. Radiation in daily life • Ionizing Radiation • Ultraviolet light from the Sun • X-ray, used for medical diagnosis

8. Non-Ionizing • Visible light • Mircowaves • Laser • Video display terminal • Radiofrequency Diathermy

9. Question Time • What are the two groups Radiation can be grouped into? Answer: Ionizing and non-Ionizing Radiation

10. Question Time 2. What are the two factors that affect the radiation and absorption? Answer: Temperature and Nature of the surface

11. Question Time 3.Name me any two examples of Radiation. Answer: Visible light, Mircowaves, Laser, Video display terminal,Radiofrequency Diathermy, Ultraviolet light, X-ray (any two)

12. Information Are From the following: • Star Publishing Pte Ltd, In Science, volume2 • http://en.wikipedia.org • http://siri.uvm.edu/ppt/rfclass/tsld005.htm

13. Pictures From: • www.bnsc.gov.uk • www.lakewoodconferences.com • www.nmsu.edu • http://www.who.int/ionizing_radiation/about/what_is_ir/en/index.html

14. Done by • Chan Wee How • Chiam Kah Wei • Kent Koo • Elvin Kwek