no
A full set of valence electrons typically consists of 8 electrons, except for hydrogen and helium, which have a full valence shell with 2 electrons.
It does.
Yes, it can.
8
An atom with 4 valence electrons will have to either gain 4 electrons or lose 4 electrons to achieve a full set of eight electrons.
Yes, it is true.
They will gain 3 electrons from something with 3 valence electrons.
An element that does not require eight electrons for a full set of valence electrons is represented by the element symbol B. Boron only needs six electrons to complete its valence shell and achieve stability.
The octet rule.
Helium has a full outermost energy level containing only two electrons.
Helium has only 2 electrons and its energy level is full.
Helium