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The frequencies of light that an atom can emit are dependent on states the electrons can be in. When excited, an electron moves to a higher energy level or orbital. When the electron falls back to its ground level the light is emitted. Emission spectrum of hydrogen. The above picture shows the visible light emission spectrum for hydrogen. If ...
Photoemission of electrons from a metal plate accompanied by the absorption of light quanta – photons. The photoelectric effect is the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons.
One example of the photo-excitation scheme is a method developed by Michael Bowers, at Vanderbilt University in Nashville, involving coating a blue LED with quantum dots that glow white in response to the blue light from the LED. This method emits a warm, yellowish-white light similar to that made by incandescent light bulbs. [32]
in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. [13] Electrons belong to the first generation of the lepton particle family, [14] and are generally thought to be elementary particles because they have no known components or substructure. [1] The electron's mass is approximately 1 / 1836 that ...
The energy and momentum of electrons in solids can be described by introducing Bloch waves into the Schrödinger equation with applying periodic boundary conditions. Solving this eigenvalue equation, one obtains sets of solutions that are describing bands of energies that are allowed to the electrons: the electronic band structure. The latter ...
Atoms can be excited by heat, electricity, or light. The hydrogen atom provides a simple example of this concept.. The ground state of the hydrogen atom has the atom's single electron in the lowest possible orbital (that is, the spherically symmetric "1s" wave function, which, so far, has been demonstrated to have the lowest possible quantum numbers).
where E is the energy of the quantum , f is the frequency of the light wave, h is the Planck constant, λ is the wavelength and c is the speed of light. The relationships between the energies of the various quantum states are treated by atomic orbital, molecular orbital, Ligand Field Theory and Crystal Field Theory.
Spectrum of a blue/green electroluminescent light source for a clock radio (similar to the one seen in the above image). Peak wavelength is at 492 nm and the FWHM spectral bandwidth is quite wide at about 85 nm. Electroluminescence is the result of radiative recombination of electrons and holes in a material, usually a semiconductor.