Octet Exceptions

[Ruiting Jia 4D]

How come H, He, Li, Be are the octet exceptions?

[Ryan Troutman 4L]

Hydrogen and Helium are exceptions to the octet rule since a full shell is only 2 electrons (1s1,1s2). Lithium and Beryllium are more likely to lose electrons instead of gain them and become cations (Li+1) and (Be+2). Hope this helps :)

[Erica Li 1C]

Just to add on to that, they follow the duplet rule as opposed to the octet rule!

[Milena Aragon 2B]

And to add on to that, the duplet rule just means that the element is looking to fill the 1s orbital since it is the most stable that way. This rule only applies to the first five elements of the periodic table.