Absorption Spectrum

Absorption spectrum is defined as: an electromagnetic spectrum in which an absorbing substance’s decrease in intensity of radiation at various wavelengths or ranges of wavelengths is expressed particularly as a pattern of black lines or bands.

Absorption spectroscopy is an analytical chemistry technique for determining the presence of a specific compound in a sample and, in many situations, quantifying the amount of that material present. In analytical applications, infrared and ultraviolet–visible spectroscopy are particularly frequent. Absorption spectroscopy is also used in molecular and atomic physics research, as well as astronomical spectroscopy and remote sensing.

Electromagnetic  spectrum

Maxwell anticipated the existence of a variety of electromagnetic waves, of which visible light waves were the only ones visible to mankind. The Electromagnetic Spectrum is the range and classification of all various forms of electromagnetic radiations based on their frequency. The Electromagnetic Spectrum is also defined as the orderly distribution of electromagnetic waves based on wavelength and frequency. EM waves travel at speeds that are similar to those of light in a vacuum, but they travel over a wide variety of wavelengths and frequencies. The Electromagnetic Spectrum refers to the range of wavelengths and frequencies that spans frequencies from below 1Hzto above 1025 Hz.

Significance of Electromagnetic Spectrum

Through his equations, Maxwell predicted the presence of limitless frequencies of electromagnetic waves, all travelling at the speed of light. This is the first evidence that the complete electromagnetic spectrum exists. Electromagnetic waves are created in a variety of ways. The different bands represent diverse properties based on how they’re made, how they interact with matter, and how they’re used. The Electromagnetic Spectrum’s fundamental relevance is that it may be used to classify electromagnetic waves and arrange them according to their various frequencies or wavelengths.

absorption spectrum

When light from a hot source with a continuous  spectrum travels through a colder gas, an absorption spectrum with absorption lines or bands is created. A substance’s absorption spectrum displays how much of the incident electromagnetic energy it absorbs over a range of frequencies. An absorption spectrum is similar to an emission spectrum in certain aspects.

Absorption lines at varied specified wavelengths correlate to the differences in the energy levels of the orbitals of each chemical element. As a result, absorption spectra can be utilised to identify components in a gas or liquid. This technique is used to infer the presence of elements in stars and other gaseous objects that can’t be measured directly.

Absorption line

A spectrum’s pattern of absorption lines can reveal the types of atoms and molecules present, such as in a star’s surface layers or a planet’s atmosphere. In the spectra of the Sun and other stars, absorption lines can be seen. The majority of them are Fraunhofer lines, but others appear in the cool interstellar gas along the line of sight and provide information about the interstellar medium’s physics and chemistry. In quasars, absorption lines carry information about intergalactic space.

Absorption band

A set of very tightly spaced absorption lines resulting from the absorption of light by molecules is known as an absorption band. In the spectra of low temperature stars (see M stars), such as red giants, bands formed by titanium dioxide and carbon compounds can be seen. In the spectra of distant stars, so-called diffuse interstellar bands can be seen, which are most likely caused by complex carbon molecules.

Absorption spectrum energy level diagram

By shining white light through a sample of a gaseous element, an Absorption Spectrum is created. Due to the absorption of energy by electrons corresponding to the element’s energy levels, the sample emission spectra will be absent from the result.

The hydrogen spectrum is as follows when current is carried via hydrogen gas:

Each element, as well as each isotope of that element, has its own line spectrum.

The amount of energy that electrons have at each level in an atom is depicted in an energy level diagram.

The energies are measured from a zero point, which corresponds to one free electron.

Because a free electron has less energy than an orbiting electron, the energies are shown as negatives in comparison to the ground state.

Conclusion

When light from a hot source, which produces a continuous spectrum, passes through a colder gas, it creates an absorption spectrum with absorption lines or bands. Absorption spectroscopy is an analytical chemistry technique for determining the presence of a specific compound in a sample.

A set of very tightly spaced absorption lines resulting from the absorption of light by molecules is known as an absorption band. By shining white light through a sample of a gaseous element, an Absorption Spectrum is created. A spectrum’s pattern of absorption lines can reveal the types of atoms and molecules present, such as in a star’s surface layers or a planet’s atmosphere. The Electromagnetic Spectrum is also defined as the orderly distribution of electromagnetic waves based on wavelength and frequency.