Light is a small section of the entire electromagnetic spectrum

Further experimentation showed that the light spectrum our eyes perceive is a very small segment of what is now called the electromagnetic spectrum. Type into your browser:

electromagnetic spectrum wavelengths images

Have students note other familiar things, e.g.,  X-rays, radio waves, are also parts of the electromagnetic spectrum. That is, their difference from light and from each other is only a matter of their wavelength. Give special attention to infrared (heat) radiation. This is particularly important when we come to a consideration of climate change.