Which noble gas has less than 8 electrons in the valence shell of its atom? What is this number?
Noble gases have eight electrons in their outermost shell, except in the case of helium, which has two.
(a) What are valence electrons? Where are valence electrons situated in an atom ?
(b) What is the number of valence electrons in the atoms of an element having atomic number 13 ? Name the valence shell of this atom.