Question

What is the difference between the octet rule and the duet rule?

Answer 1

The rule of duet refers to the first five elements of the periodic table. They are most stable when the 1s orbital is filled with two (duet) electrons. Hydrogen looks to gain one electron, Lithium, Beryllium and Boron look to lose 1,2, or 3 electrons respectively in order to have a filled outer shell like Helium.

The rule of octet refers to the filling of the s and p orbital with eight (octet) electrons in order to become stable like a noble gas `s^2 p^6`.
Elements look to lose or gain electrons in order to be like a noble gas. In doing so non-metals take on electrons and become negative anions while metals tend to lose electrons and become positive cations.

I hope this was helpful.
SMARTERTEACHER