The valence electron of a neutral sodium atom in its ground state is in the 3s sublevel.
Sodium has an atomic number of 11, which is the number of protons in the nuclei of its atoms. A neutral sodium atom also has 11 electrons.
The electron configuration of a neutral sodium atom is 1s22s22p63s1.
For the atoms of the representative elements (all elements except for the inner and outer transition metals), their valence electrons are in their outermost (highest energy) s and p sublevels.
Therefore, the valence electron of a neutral sodium atom in its ground state is in its 3ssublevel, in which 3 represents the principal energy level, and s represents the sublevel
first calculate molarmass by using d=z×m/a3 × na
then calculate moles 1/ molar mass
and finally multiply it by na