Electron in the outer shell of an atom's energy levels
Four covalent bonds. Carbon has four valence electrons and here a valence of four. Each hydrogen atom has one valence electron and is univalent.
In chemistry and physics, valence electrons are electrons in the outermost shell of an atom, and that can participate in the formation of a chemical bond if the outermost shell is not closed. In a single covalent bond, a shared pair forms with both atoms in the bond each contributing one valence electron.
The presence of valence electrons can determine the element's chemical properties, such as its valence—whether it may bond with other elements and, if so, how readily and with how many. In this way, a given element's reactivity is highly dependent upon its electronic configuration. For a main-group element, a valence electron can exist only in the outermost electron shell; for a transition metal, a valence electron can also be in an inner shell.
An atom with a closed shell of valence electrons (corresponding to a noble gas configuration) tends to be chemically inert. Atoms with one or two valence electrons more than a closed shell are highly reactive due to the relatively low energy to remove the extra valence electrons to form a positive ion. 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. An energy gain can trigger the electron to move (jump) to an outer shell; this is known as atomic excitation. Or the electron can even break free from its associated atom's shell; this is ionization to form a positive ion. When an electron loses energy (thereby causing a photon to be emitted), then it can move to an inner shell which is not fully occupied.
main-group element, a valenceelectron can exist only in the outermost electron shell; for a transition metal, a valenceelectron can also be in an inner...
Valence shell electron pair repulsion (VSEPR) theory (/ˈvɛspər, vəˈsɛpər/ VESP-ər,: 410 və-SEP-ər) is a model used in chemistry to predict the geometry...
conductivity of the solid. In nonmetals, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero...
both valenceelectron count and valence orbital type. As chemical reactions involve the valenceelectrons, elements with similar outer electron configurations...
Free electron in physics may refer to: Electron, as a free particle Solvated electron Charge carrier, as carriers of electric charge Valenceelectron, as...
electrons are the electrons in an atom that are not valenceelectrons and do not participate in chemical bonding. The nucleus and the core electrons of...
the valence shell of the atom; a group 17 atom releases more energy than a group 1 atom on gaining an electron because it obtains a filled valence shell...
hybridization. Valence bond theory complements molecular orbital theory, which does not adhere to the valence bond idea that electron pairs are localized...
the atoms share "valence", such as is discussed in valence bond theory. In the molecule H 2, the hydrogen atoms share the two electrons via covalent bonding...
an open shell is a valence shell which is not completely filled with electrons or that has not given all of its valenceelectrons through chemical bonds...
and the "rule of eight", which began to distinguish between valence and valenceelectrons. In 1919, Irving Langmuir refined these concepts further and...
In chemistry, electron counting is a formalism for assigning a number of valenceelectrons to individual atoms in a molecule. It is used for classifying...
other electron state in the valence band. A hole near the top of the valence band moves the same way as an electron near the top of the valence band would...
octet rule because they have too few valenceelectrons and species that happen to follow the octet rule but have electron-acceptor properties, forming donor-acceptor...
energetic properties of electrons as molecular orbitals that surround two or more atoms in a molecule and contain valenceelectrons between atoms. Molecular...
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 —...
affected by both its atomic number and the distance at which its valenceelectrons reside from the charged nucleus. The higher the associated electronegativity...
be seen as the result of different behaviors of the outermost or valenceelectrons of atoms. These behaviors merge into each other seamlessly in various...
the number of valenceelectrons of the neutral atom in isolation (in its ground state); L is the number of non-bonding valenceelectrons assigned to this...
valence band. Semiconductors and insulators are distinguished from metals because the valence band in any given metal is nearly filled with electrons...
other chemical substances, results from their electron configuration: their outer shell of valenceelectrons is "full", giving them little tendency to participate...
In chemistry, a lone pair refers to a pair of valenceelectrons that are not shared with another atom in a covalent bond and is sometimes called an unshared...
the electrons. In hydrogen, or any other atom in group 1A of the periodic table (those with only one valenceelectron), the force on the electron is just...
the electrons in the valence band are always moving around, a completely full valence band is inert, not conducting any current. If an electron is taken...
is due to the fact that gadolinium valence d-subshell borrows 1 electron from the valence f-subshell. Now the valence subshell is the d-subshell, and due...
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