1. What do I know about radiation? Activity 1: Discuss the following questions in pairs and write down your answers on the worksheet ‘What is radiation?’ 1.Have you heard the term ‘radiation’ before? What do you think it means? 2.Can you think of any examples of types of radiation? 3.Is radiation is dangerous? Give reasons for your answer. 4.Is radiation useful? Give reasons for your answer.

2. What is Radiation? Learning outcomes: 1.Recall prior knowledge of radiation. 2.Identify and describe radiation emitted by a light bulb. 3.Be able to list 4 key properties of radiation.

3. Radiation from a bulb In your groups, switch on the bulb and discuss the following questions: 1.What is being emitted by the bulb? 2.In which direction? 3.Move your hand closer to the bulb. Position a sheet of paper close to the bulb, then slowly move the paper away. What do you notice about the change in intensity as you move closer or further away from the bulb? Write your answers in your books.

4. Radiation from a bulb You should have been able to detect 2 forms of radiation emitted by the bulb: 1.visible light 2.infrared radiation (cannot be seen but can be detected by its heating effect) Radiation is emitted from the bulb in all directions.

5. Why the word ‘radiation’? radius The word radiation comes from the Latin word radius - meaning a spoke of a wheel. The word radius was later shortened to the word ray – for example a ray of light. Radiation can be represented as rays - straight lines showing the pathways of the radiation. We can say that radiation is emitted from a source radially – that is in all directions.

6. Intensity of radiation What did you notice about the brightness of the light and the strength of the heating effect as you moved further away from the bulb? The intensity of radiation decreases with distance from the source. Fewer rays hit your hand when it is further away from the source.

7. Key properties of radiation 1.Radiation is emitted from a central source. 2.It spreads out or radiates in all directions. 3.Energy is transferred away from the source through radiation. 4.The intensity of radiation decreases as you move further away from the source.

8. Learning objectives revisited: 1.Recall prior knowledge of radiation. 2.Identify and describe radiation emitted by a light bulb. 3.Propose examples of sources of radiation in nature.