☯ Concept Cartoons ☯
Table of Contents
1 Chemistry IR and Colorimetry, spectroscopy 11 - What is electromagnetic radiation?
Have you talked about your ideas? Do you agree with any of the characters or do you think something different? Do you all have the same ideas? Here are some ways of finding out more. Find a picture of the electromagnetic spectrum. Discuss what you know about the parts that you recognise. Do some research to find out exactly what the spectrum is. Talk about what life would be like if we didn’t know how to use electromagnetic radiation. Use the internet to find out why some of the radiation that we can’t see helps us to observe the Universe and find out more about it.
Here’s what a scientist might say. Did you find any evidence to support or justify these ideas? Are there any questions that you still need to answer? Electromagnetic radiation can be thought of as a wave made from electric and magnetic fields that travel at the speed of light. It includes a wide spectrum from radio waves to gamma rays, arranged in order of their wavelength. It is all the same type of radiation, even though the wavelength varies. We can only see a small part of the electromagnetic spectrum, called visible light. Radio waves have the longest wavelength, then, in order, microwaves, infrared and visible light. After visible light comes ultraviolet, x-rays and finally gamma rays. Infrared radiation is emitted by hot objects; this is what makes us feel warm in the sunshine or standing next to a barbeque. Ultraviolet radiation has a much shorter wavelength and is the radiation that causes sunburn when our skin is exposed to it. Create a chart to show the different parts of the spectrum and how each type of radiation can be used.