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  2. Octet rule - Wikipedia

    en.wikipedia.org/wiki/Octet_rule

    The quantum theory of the atom explains the eight electrons as a closed shell with an s 2 p 6 electron configuration. A closed-shell configuration is one in which low-lying energy levels are full and higher energy levels are empty. For example, the neon atom ground state has a full n = 2 shell (2s 2 2p 6) and an empty n = 3 shell. According to ...

  3. Valence electron - Wikipedia

    en.wikipedia.org/wiki/Valence_electron

    An atom with one or two electrons fewer than a closed shell is reactive due to its tendency either to gain the missing valence electrons and form a negative ion, or else to share valence electrons and form a covalent bond. Similar to a core electron, a valence electron has the ability to absorb or release energy in the form of a photon.

  4. Valence (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Valence_(chemistry)

    The valence is the combining capacity of an atom of a given element, determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of 2; and in hydrogen chloride, chlorine has a valence of 1. Chlorine, as it has a valence of one ...

  5. Effective nuclear charge - Wikipedia

    en.wikipedia.org/wiki/Effective_nuclear_charge

    Description. The effective atomic number Z eff, (sometimes referred to as the effective nuclear charge) of an atom is the number of protons that an electron in the element effectively 'sees' due to screening by inner-shell electrons. It is a measure of the electrostatic interaction between the negatively charged electrons and positively charged ...

  6. Nuclear shell model - Wikipedia

    en.wikipedia.org/wiki/Nuclear_shell_model

    In nuclear physics, atomic physics, and nuclear chemistry, the nuclear shell model utilizes the Pauli exclusion principle to model the structure of atomic nuclei in terms of energy levels. [ 1 ] The first shell model was proposed by Dmitri Ivanenko (together with E. Gapon) in 1932. The model was developed in 1949 following independent work by ...

  7. Fluorine compounds - Wikipedia

    en.wikipedia.org/wiki/Fluorine_compounds

    While an individual fluorine atom has one unpaired electron, molecular fluorine (F 2) has all the electrons paired.This makes it diamagnetic (slightly repelled by magnets) with the magnetic susceptibility of −1.2×104 (), which is close to theoretical predictions. [5]

  8. Molar ionization energies of the elements - Wikipedia

    en.wikipedia.org/wiki/Molar_ionization_energies...

    This is the energy per mole necessary to remove electrons from gaseous atoms or atomic ions. The first molar ionization energy applies to the neutral atoms. The second, third, etc., molar ionization energy applies to the further removal of an electron from a singly, doubly, etc., charged ion. For ionization energies measured in the unit eV, see ...

  9. Ionic bonding - Wikipedia

    en.wikipedia.org/wiki/Ionic_bonding

    4 or SO 2− 4. In simpler words, an ionic bond results from the transfer of electrons from a metal to a non-metal to obtain a full valence shell for both atoms. Clean ionic bonding — in which one atom or molecule completely transfers an electron to another — cannot exist: all ionic compounds have some degree of covalent bonding or electron ...