He, Li and Be

[Anna De Schutter - 1A]

Hi!

I'm a bit confused, how are He, Li and Be exceptions to the octet rule? If they don't aim to have 8 valence electrons, what do they do then?

Thank you!
Anna De Schutter - section 1A

[Priscilla Okaiteye]

Okay, so Helium only has 2 electrons which means it doesn't need 8 or an octet. It is a noble gas. All its shells are filled. Now Lithium and beryllium are sort of the same in the sense that they don't need 8 electrons. They do give away valence electrons to have their next shell filled.

[Maria Roman 1A]

generally the rule is that below period three, the elements will be exempt from the octet rule

[Carlos De La Torre 2L]

The rule is that below the third period the octet rule is followed (except for the first 4 elements), but after is when extended orbitals come into play