An absorption spectrum is a graph that shows the wavelengths of light that are absorbed by a substance. It is created by passing a beam of white light through a sample of the substance and measuring the wavelengths of light that are absorbed.
An emission spectrum is a graph that shows the wavelengths of light that are emitted by a substance. It is created by heating the substance and measuring the wavelengths of light that are emitted. An absorption spectrum shows the wavelengths of light that are absorbed, while an emission spectrum shows the wavelengths of light that are emitted.
Sodium is commonly used because it is a highly reactive element that produces distinct and easily observable spectra. It also has many practical applications, such as in street lights and flame tests.
An absorption spectrum is like a unique fingerprint for a substance. Each substance has its own specific pattern of wavelengths that are absorbed, allowing scientists to identify the substance through its spectrum. This is especially useful in identifying unknown substances in a mixture.
Absorption and emission spectra can also be used in astronomy, as they can provide information about the composition and temperature of stars and other celestial objects. They are also used in environmental science to analyze the composition of gases in the atmosphere.