Question

What would be the electronic configuration of a positively charged sodium ion, $Na$? What would be its atomic number and mass number?

Answer 1

Number of electrons in $Na$ atom = Atomic number = 11
Number of electrons in $N{a}^{+}$ ion = 11-1 = 10
Electronic configuration of $N{a}^{+}$ ion: $1s^{2}2s^{2}2p^6$
Mass number of $Na$ = 22 atomic mass units.