8, except for helium which has 2 valence electrons
Helium has 2 valence electrons. All other noble gases have 8 valence electrons.
Because all noble gases have completely filled valence orbitals. Helium has 2 valence electrons whereas all other noble gases have 8 valence electrons.
Noble gases have completely filled orbitals / energy levels. They generally have 8 valence electrons (helium has only 2 valence electrons) and have stable electronic configuration.
Valence electrons are electrons in the outermost shell (or outermost energy level or outermost orbital) in an atom. Noble gases have 8 valence electrons. But helium (a noble gas) has only 2 valence electrons.
Helium has only 2 valence electrons. The rest noble gases have eight.
Group 18 contains eight valence electrons, namely the noble gases.
All noble gases have 8 valence electrons. Helium has only 2.
These are the noble gases.
Helium is the noble gas with only 2 valence electrons
Inert gases have 8 valence electrons. This is why they are inert, they have a complete octet formed of electrons and are in their lowest energy configuration.
eight
Noble gases have completely filled orbitals / energy levels. They generally have 8 valence electrons (helium has only 2 valence electrons) and have stable electronic configuration.