Explain the process of formation of ionic compounds and their Lewis structures. MgCl2, Na2O, MgO
The Correct Answer and Explanation is:
Formation of Ionic Compounds and Their Lewis Structures: MgCl₂, Na₂O, MgO
Ionic compounds are formed through the transfer of electrons between metals and nonmetals. Metals, which have few valence electrons, tend to lose electrons and form positively charged ions called cations. Nonmetals, with more valence electrons and a high affinity for electrons, tend to gain electrons and form negatively charged ions called anions. This transfer creates ions with opposite charges, which are held together by strong electrostatic forces known as ionic bonds.
Formation of MgCl₂ (Magnesium Chloride)
Magnesium (Mg) has two valence electrons (electron configuration: [Ne] 3s²), and each chlorine (Cl) atom has seven valence electrons (electron configuration: [Ne] 3s²3p⁵). Magnesium loses its two electrons to become Mg²⁺, and each chlorine atom gains one electron to become Cl⁻. Since magnesium donates two electrons, two chlorine atoms are needed:
Mg → Mg²⁺ + 2e⁻
2Cl + e⁻ → 2Cl⁻
Lewis Structure:
Mg²⁺ is shown as [Mg]²⁺ (no dots).
Each Cl⁻ is shown as [Cl]⁻ with a complete octet (8 dots).
Structure: [Mg]²⁺ [Cl]⁻ [Cl]⁻
Formation of Na₂O (Sodium Oxide)
Sodium (Na) has one valence electron ([Ne] 3s¹), and oxygen has six valence electrons ([He] 2s²2p⁴). Each sodium atom loses one electron to form Na⁺, and oxygen gains two electrons to form O²⁻. Two sodium atoms are required to provide two electrons:
2Na → 2Na⁺ + 2e⁻
O + 2e⁻ → O²⁻
Lewis Structure:
Each Na⁺ is [Na]⁺ (no dots), O²⁻ is [O]²⁻ with 8 electrons (dots).
Structure: [Na]⁺ [O]²⁻ [Na]⁺
Formation of MgO (Magnesium Oxide)
Magnesium loses two electrons to form Mg²⁺, and oxygen gains two electrons to form O²⁻. One magnesium atom bonds with one oxygen atom:
Mg → Mg²⁺ + 2e⁻
O + 2e⁻ → O²⁻
Lewis Structure:
[Mg]²⁺ (no dots), [O]²⁻ with full octet.
Structure: [Mg]²⁺ [O]²⁻
In summary, ionic compounds form when metals transfer electrons to nonmetals, resulting in stable electron configurations for both ions. Their Lewis structures show complete octets for the anions and indicate the charge of each ion.
