index - Electron configuration 1 Electron configuration In...

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Electron configuration 1 Electron configuration Electron atomic and molecular orbitals In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure. [1] It concerns the way electrons can be distributed in the orbitals of the given system (atomic or molecular for instance). Like other elementary particles, the electron is subject to the laws of quantum mechanics, and exhibits both particle-like and wave-like nature. Formally, the quantum state of a particular electron is defined by its wave function, a complex-valued function of space and time. According to the Copenhagen interpretation of quantum mechanics, the position of a particular electron is not well defined until an act of measurement causes it to be detected. The probability that the act of measurement will detect the electrons at a particular point in space is proportional to the square of the absolute value of the wavefunction at that point. An energy is associated with each electron configuration and, upon certain conditions, electrons are able to move from one orbital to another by emission or absorption of a quantum of energy, in the form of a photon. Knowledge of the electron configuration of different atoms is useful in understanding the structure of the periodic table of elements. The concept is also useful for describing the chemical bonds that hold atoms together. In bulk materials this same idea helps explain the peculiar properties of lasers and semiconductors. Shells and subshells Electron configuration table Electron configuration was first conceived of under the Bohr model of the atom, and it is still common to speak of shells and subshells despite the advances in understanding of the quantum-mechanical nature of electrons. An electron shell is the set of allowed states electrons may occupy which share the same principal quantum number, n (the number before the letter in the orbital label). An atom's n th electron shell can accommodate 2 n 2 electrons, e.g. the first shell can accommodate 2 electrons, the second shell 8 electrons, and the third shell 18 electrons. The factor of two arises because the allowed states are doubled due to electron spin each atomic orbital admits up to two otherwise identical electrons with opposite spin, one with a spin +1/2 (usually noted by an up-arrow) and one with a spin -1/2 (with a down-arrow). A subshell is the set of states defined by a common azimuthal quantum number, l , within a shell. The values l = 0, 1, 2, 3 correspond to the s , p , d , and f labels, respectively. The maximum number of electrons which can be placed in a subshell is given by 2(2 l + 1). This gives two electrons in an s subshell, six electrons in a p subshell, ten electrons in
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Electron configuration 2 a d subshell and fourteen electrons in an f subshell. The numbers of electrons that can occupy each shell and each subshell arise from the equations of quantum
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This note was uploaded on 10/25/2010 for the course FOSEE CVL1040 taught by Professor None during the Spring '09 term at Multimedia University, Cyberjaya.

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index - Electron configuration 1 Electron configuration In...

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