Explain the formation of an ionic compound between metal and a non – metal by transfer of electrons with Mg as the metal and Cl as a non – metal to illustrate your answer.

Ans. Magnesium is a metal whereas chlorine is a non – metal. Magnesium reacts with chlorine to form an ionic compound magnesium chloride.

The atomic number of magnesium is 12, so its electronic configuration is 2,8,2. It has 2 valance electrons. A magnesium atom donates its 2 valence electrons (to two chlorine atoms) and forms a stable magnesium ion, Mg^2+.

Mg	-	2e –	→	Mg2+
Magnesium atom		electrons		Magnesium ion
				(2 , 8)

The atomic number of chlorine is 17, and its electronic configuration is 2,8,7. Chlorine atom has 7 valance electrons, so it requires only 1 more electrons to complete its octet. Since, one magnesium atom donates 2 electrons, so, two chlorine atoms take these two electrons and form two chloride ions.

2Cl	+	2e –	→	2Cl–
two chlorine atoms		electrons		two chloride ions
2, 8, 7				2(2 , 8, 8)

The positively charged magnesium ions and negatively charged chloride ions are held together by electrostatic force of attraction to form magnesium chloride (MgCl₂) compound.