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Spectroscopy

Key Stage 4

Meaning

Spectroscopy is a technique used to identify elements and compounds by the wavelengths of light they either absorb or emit.

About Spectroscopy

When white light passes through a spectroscope the colours are split into a spectrum (the rainbow).
If white light passes through a gas before it reaches the spectroscope the chemicals in the gas will absorb certain wavelengths of light that are unique to the chemicals in that gas. When this light is passed through a spectroscope it produces an absorption spectrum that appears as a rainbow but with dark lines at specific wavelengths.
If the electrons in a chemical gain energy they can move up to a higher electron orbital. When they fall back down to the lower electron orbital they release a specific wavelengths of light. When this light is passed through a spectroscope it produces an emission spectrum or a line spectrum that appears as a series of lines of specific wavelengths.

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