atomic spectrum

American  

noun

1. the spectrum of electromagnetic radiation characteristically absorbed or emitted by an atom of a particular element when its electrons jump to a higher or lower energy level.

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atomic spectrum Scientific  

1. The range of characteristic frequencies of electromagnetic radiation that are readily absorbed and emitted by an atom. The atomic spectrum is an effect of the quantized orbits of electrons around the atom. An electron can jump from one fixed orbital to another: if the orbital it jumps to has a higher energy, the electron must absorb a photon of a certain frequency; if it is of a lower energy, it must give off a photon of a certain frequency. The frequency depends on the difference in energy between the orbitals. Explaining this phenomenon was crucial to the development of quantum mechanics. The atomic spectrum of each chemical element is unique and is largely responsible for the color of matter. Atomic spectra can also be analyzed to determine the composition of objects, such as stars, that are far away.

2. See more at orbital See also spectrum

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Example Sentences

Figure 30.14 Niels Bohr, Danish physicist, used the planetary model of the atom to explain the atomic spectrum and size of the hydrogen atom.

From Textbooks • Aug. 12, 2015

An antiatom, for example, composed of positrons, antiprotons, and antineutrons should have the same atomic spectrum as its matter counterpart.

From Textbooks • Aug. 12, 2015

Bohr’s theory explained the atomic spectrum of hydrogen and established new and broadly applicable principles in quantum mechanics.

From Textbooks • Aug. 12, 2015