Octet rule

From Sajun.org

The octet rule is a simple chemical theory that states that atoms tend to combine in such a way that they have eight electrons in their valence shells, similar to the electronic configuration of a noble gas. (In simple terms, molecules are more stable when the outer shells of their constituent atoms are empty, full, or have a multiple of 8 electrons in the outer shell. See electron shells.) This combination occurs primarily in two ways, electrovalent bonding and covalent bonding. However, the octet rule is often inapplicable. Some of the atoms for which the octet rule are most useful are: * carbon, C * oxygen, O * the halogens However, the exceptions are plenty: * hydrogen only needs one electron to have a noble gas structure (that of helium), and lithium needs to lose one. * any molecule or ion with an odd number of electrons * any atom that forms more than four bonds (phosphorus falls under this as well as the rule below) * the octet rule is inapplicable to atoms in periods greater than 2 because their electron shells can hold more than eight electrons * boron is an exception with extreme frequency * there are a few special cases in very common substances, notably carbon monoxide and ozone ==See also== * Lewis structure ja:オクテット則 

옥텟 규칙분자를 이루는 각각의 원자최외각 껍질에 8개가 들어갔을 때 가장 안정된 상태라고 하는 화학 이론이다.

이는 탄소·산소·할로겐 원소 등에는 유용하게 쓸 수 있지만 그밖의 원소에는 예외가 많다.