The Chemistry Book

Lesson Content

Octet and Duet Rule

1.Definition
Octet rule states that most representative atoms tend to combine in such a way that they each have eight electrons in their valence shell.
Duet rule similar to Octet rule but for the first energy level elements

2.Octet Rule
Represantive elements, also called main group elements, have the same noble gas configuration. The octet rule works with elements in the second row of nonmetals. Carbon-fluorine form stable molecules when surrounded by enough electrons to fill the valence orbitals. Eight electrons are required to fill these orbitals. Carbon, nitrogen, oxygen, and fluorine almost always obey the octet rule in stable molecules.

3.Duet Rule
First energy level elements are hydrogen and helium, the energy level is found by period/ row it is in. Hydrogen forms stable molecules where it shares two electrons and helium doesn't form bonds because its valence orbitals are already filled.