octet rule


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octet rule

[äk‚tet ‚rül]
(chemistry)
A concept of chemical bonding theory based on the assumption that in the formation of compounds, atoms exhibit a tendency for their valence shells either to be empty or to have a full complement of eight electrons (octet); for some elements there are more than the usual eight valence electrons in some of their compounds.
References in periodicals archive ?
It states that a nitrogen atom cannot have five covalent bonds, as this would break the 'octet rule' which is a central part of Lewis's theory.
In doing so, the compounds break the octet rule, which states that atoms in the first rows of the periodic table tend to form bonds that complete a set of eight electrons in the outskirts of their electron cloud.
It's narrower, for one thing, since the octet rule doesn't hold.
"The octet rule is likely the most useful way in explaining bonding when learning chemistry.
The basic 'formula' of the octet rule is straight forward: each atom tries to have four pairs (8 electrons) around it in order to assume the stable state of the noble gases.
The traditional picture of its bonds relies on the pre-1920 Lewis-Langmuir octet rule, which requires that eight electrons surround each of [SO.sub.3]'s four atoms.