Create a rule about how many valence electrons an atom will have

Most of the elements have their 8 electrons in its outermost shell this shell is called valence shell.

The most of elements containg 8 electrons to their valence shell are mostly stable in nature and rule obey octet rule the is 3n subshell surrounds 18 electrons.

e. g Nobel gases shows octet rules.

since electrons are negative the answer is neagtaive