Explain why ionic compounds are formed when a metal from the left side of the periodic table reacts with a nonmetal from the right side. Give two examples of such compounds.
Ionic compounds are formed when a metal from the left side of the periodic table reacts with a nonmetal from the right side because of the difference in their electronegativity. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. Metals, located on the left side of the periodic table, have low electronegativity, meaning they have a tendency to lose electrons and form positively charged ions called cations. Nonmetals, found on the right side of the periodic table, have high electronegativity, indicating they have a tendency to gain electrons and form negatively charged ions called anions.
The formation of ionic compounds occurs through a transfer of electrons from the metal to the nonmetal. The metal loses electrons to become a more stable cation, and the nonmetal gains those electrons, becoming a more stable anion. The resulting cations and anions are attracted to each other by electrostatic forces, creating a bond between them.
Two examples of ionic compounds formed when a metal reacts with a nonmetal include:
1. Sodium Chloride (NaCl): Sodium, a metal from Group 1 of the periodic table, readily loses one electron to achieve a stable electron configuration. Chlorine, a nonmetal from Group 17, readily gains one electron to achieve a stable electron configuration. The transfer of this electron from sodium to chlorine forms the ionic compound sodium chloride.
2. Magnesium Oxide (MgO): Magnesium, a metal from Group 2, loses two electrons to achieve a stable electron configuration. Oxygen, a nonmetal from Group 16, readily gains two electrons to achieve a stable electron configuration. The transfer of these electrons from magnesium to oxygen forms the ionic compound magnesium oxide.
In summary, when a metal from the left side of the periodic table reacts with a nonmetal from the right side, ionic compounds are formed through the transfer of electrons, resulting in the formation of cations and anions that are held together by electrostatic forces.