Differentiate between Na and Na+.

Na is symbol of normal sodium atom which have 11 protons in nucleus , with electronic configuration (2,8,1) having total 11 electrons in its all 3 shells. in this condition because nucleus have 11 protons, it have 11 unit positive charge and because of 11 electrons it have 11 unit negative charge . Because of equal number of positive charge and negative charge they cancel each other . that's why normal sodium atom (Na) is electrically neutral. But Na+ is positive ion of sodium. during chemical reaction sodium atom (Na) loses his one electron present last orbit. because only one electron is present in its last orbit , it is 3rd orbit . by losing this electron 3rd orbit loses its existence and second orbit having 8 electrons become outermost orbit and in this way it becomes stable. But now this atom have 10 electrons that is 10 negative charge and 11 protons that is 11 positive charge. in this condition number of positive charge is 1 unit more than negative charge . that's why sodium atom get unit positive change and sodium single positive (Na+) ion forms.