Ionic compounds conduct electricity better than covalent compounds due to the fundamental difference in their chemical composition and bonding. Ionic compounds are composed of positively and negatively charged ions, while covalent compounds consist of electrically neutral molecules.
To understand why ionic compounds conduct electricity, we need to consider the nature of their bonding. Ionic bonding occurs when one or more electrons are transferred from a metal atom to a non-metal atom, resulting in the formation of positively charged cations and negatively charged anions. These oppositely charged ions are held together by strong electrostatic forces, creating a lattice structure.
When an ionic compound is dissolved in water or melted, the ions are free to move and carry electrical charge. This is because the polar water molecules surround and separate the ions, allowing them to dissociate and become mobile. The movement of charged particles enables the flow of electricity, as the ions can carry electric current from one point to another.
In addition to dissolution in water, ionic compounds also conduct electricity when molten. In the molten state, the strong electrostatic forces between ions are weakened, allowing the ions to move more freely. This movement of ions enables the flow of electric current through the molten ionic compound.
On the other hand, covalent compounds consist of atoms that share electrons in a covalent bond, resulting in the formation of discrete molecules. These molecules are electrically neutral, as the shared electrons are attracted to the nuclei of both atoms involved in the bond. As a result, covalent compounds do not dissociate into ions when dissolved in water or melted.
Since covalent compounds do not dissociate into ions, they do not have freely moving charged particles that can conduct electricity. Instead, covalent compounds can only conduct electricity when they are ionized or undergo a chemical reaction that generates charged species.
The ability of ionic compounds to conduct electricity is attributed to their formation of oppositely charged ions, which are free to move and carry electrical charge when dissolved in water or melted. Covalent compounds, being composed of electrically neutral molecules, do not dissociate into ions and therefore do not conduct electricity as effectively as ionic compounds.