Check for Understanding

Answer the following questions to see how much you know about electromagnetic radiation.

1. What is electromagnetic radiation?
   
   Electromagnetic radiation is any one of the seven electromagnetic energies that travel in waves at the speed of light. The energies have different wavelengths and different properties. The seven energies in the electromagnetic spectrum are gamma rays, X-rays, ultraviolet rays, visible light, infrared rays, microwaves, and radio waves.
   
   
2. Where would I find electromagnetic radiation?
   
   Radiation is everywhere. It is given off by any source of energy. Examples are microwaves from a microwave cooking unit, visible light from the sun, X-rays used for diagnosis, ultraviolet rays from the sun.
   
   
3. Is radiation all the same?
   
   Radiation differs by wavelength and has different properties. See the diagram for the different types of radiation.
   
   
4. List some types of electromagnetic energies and give an example of how you have experienced them.
   
   Student answers could include:
   - Radio waves: listening to a radio in the car
    - X-rays: diagnosis for a broken bone
    - Microwaves: cooking food
    - Ultraviolet rays: getting sunburned
    - Infrared rays: feeling the heat from the sun
    - Visible light: seeing in the light
   
   
5. Why is it important to monitor the radiation levels on board the space station?
   
   Astronauts on board the space station live and work above Earth’s protective atmosphere. Radiation can be dangerous to the cells in their bodies and has to be strictly monitored. Strategies to shield the astronauts from the radiation have to be taken if the radiation is too high.