Question

Explain the formation of (i) sodium ion, and (ii) chloride ion, from their respective atoms giving the number of protons and number of protons and number of electrons in each one of them. What is the reason for positive charge on a sodium ion and a negative charge on a chloride ion?

Answer 1

(i) Electronic configuration of sodium(Na) is 2, 8, 1. To attain noble gas configuration sodium atom will lose one electron and form sodium ion. As sodium loses one electron due to which sodium gets a positive charge on it.

Na = 2, 8, 1
Number of protons = 11
Number of electrons = 11
Na^$+$ = 2, 8
Number of protons = 11
Number of electrons = 10

(ii) Electronic configuration of chlorine(Cl) is 2, 8, 7. To attain noble gas configuration chlorine atom will gain one electron and form chloride ion. As chlorine gain one electron due to which chlorine gets a negative charge on it.

Cl = 2, 8, 7
Number of protons = 17
Number of electrons = 17
Cl^$-$ = 2, 8, 8
​Number of protons = 17
Number of electrons = 18