This is a chemical rule that states that atoms of low atomic number combine in such a way they have eight electrons in their valence shells. This is seen in carbon and oxygen when they bond in carbon dioxide. The two oxygens each supply six electrons and the carbon supplies four. By bonding, there is a sharing between them of electrons, resulting in 8 in the valence shell of all the atoms, following the octet rule. Helium however, only has room for two electrons in its only valence shell and it is stable. Therefore, it doesn not follow the octet rule.
The octet rule is a bonding theory used to predict the molecular structure of covalently bonded molecules.
The octet rule says that atoms tend to gain, lose or share electrons so as to have eight electrons in their outer electron shell.
Octet means 8, Octet rule refers to the number of electrons surounding the bond.
Atomic number of Helium is 2, so there is no chance for He to attain octet configuration since it has room for only 2 electrons.
and Octet rule is refered to the elements which can form compounds, since Helium doesn't form any compounds the octet rules is not valied for Helium, but still if we are talking of fulfilling the octet rule He doesn't fulfill the octet rule since it can accommodate maxium two electrons.
Exceptions for octet rule are Hydrogen, beryllium, boron only have too few electrons to form an octet.
Octet rule states that element generally tends to attend octet state that is 8 electron in their valance shell to atain a stable state. this can be achieved by lossing/gaining or sharing of electron.
but their are certain element that doest not follow this rule like Xe in XeCl4.
Apart from these, hydrogen and helium are one of them. They do not follow as these two element has 1s orbital only or K-shell which can hold maxium of 2 electron. so they donot follow octet rule
All elements fulfill the octet rule. This means that they all want to have a complete energy level of electrons (i.e, first shell 2 electrons, second shell 8, third shell 18 and so on). Helium is a noble gas and it has two electrons. This fills up the first shell completely so it is relatively unreactive since it does not need to gain or lose any more electrons.