A spectrum is a range of different wavelengths of electromagnetic radiation.
The white light of sunlight can be broken up into its full spectrum of colors with a triangular block of glass called a prism. The prism is set in a dark room and lit only by a shaft of sunlight or similar white light.
The prism refracts (bends) short wavelengths of light more than longer wavelengths, so the light fans out in bands ranging from violet to red.
The order of colors in a spectrum is always the same: red, orange, yellow, green, blue, indigo, violet. Electricity, magnetism and radiation
Scientists remember the order of the colors with the first letter of each word in this ancient phrase: ‘Richard Of York Gained Battles In Vain.’
Infrared is red light made of waves that are too long for human eyes to see.
Ultraviolet is violet light made of waves that are too short for our eyes to see.
Spectroscopy, or spectral analysis, is the study of the spectrum created when a solid, liquid or gas glows.
Every substance produces its own unique spectrum, so spectroscopy helps to identify substances.
Spectral analysis can reveal what anything from a distant galaxy to a drug is made of.