elements of the 1 rst and 7 th main group in the periodic system have the tendency to attain 8 electrons in their outermost shell when they form chemical bonds.
There is reason to believe that it is the outer electrons which are involved to the greatest extent in chemical reactions. With the exception of the first shell, which is complete after two electrons, each atom seems able to hold a maximum of eight electrons in the outermost part of the atom. Using these two speculations it is tempting to postulate that when elements react, they do so in such a manner that each atom obtains an outer configuration consisting of eight electrons. This generalization is called the octet rule.
elements are more stable if they have an inert gas configuration
This states that "each atom in a molecule acquires shares in electrons until its valence shell achieves eight electrons".
When atoms form bonds, they do so in a manner that will complete their valence shells. For most elements, a completed valence shell consists of eight electrons. The octet rule is the tendency of atoms in molecules to have eight electrons in their valence shells. Some common elements which do not follow the octet rule are hydrogen (H) which needs only two electrons to complete its shell, and boron (B) which only needs six electrons.
OC-tet ROOL The tendency of an atom to fill its outermost shell. 35
Many representative elements attain at least a share of eight electrons in their valence shells when they form molecular or ionic compounds; there are some limitations.
the tendency of atoms in molecules to have eight electrons in their valence shells (two for hydrogen atoms).
This states that when atoms bond together, they attain the stable structure of having eight electrons in the outer shell of their atoms. However, the Octet Rule is nothing more than just a guide and there are many exceptions to it.
the observation that atoms of nonmetals form the most stable molecules when they are surrounded by eight electrons (to fill their valence orbitals).
During bonding atoms tend to reach an electron arrangement with eight electrons in the outermost shell.
main-group elements tend to undergo reactions that leave them with 8 valence electrons
A guideline for building Lewis structures that states that atoms tend to gain, lose, or share valence electrons with other atoms in a molecule until they hold or share eight valence electrons. The octet rule almost always holds for carbon, nitrogen, oxygen, and fluorine; it is regularly violated for other elements.
atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons.
A term describing the distribution of valence electrons that takes place in chemical bonding for most elements, which end up with eight valence electrons. Hydrogen is an exception, and follows the duet rule.
The octet rule is a simple chemical rule of thumb that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas. The rule is applicable to the main-group elements, especially carbon, nitrogen, oxygen, and the halogens, but also to metals such as sodium or magnesium. In simple terms, molecules or ions tend to be most stable when the outermost electron shells of their constituent atoms contain eight electrons.