Answer:
Because of the close sharing of pairs of electrons (one electron from each of two atoms), covalent bonds are stronger than ionic bonds.
Step-by-step explanation:
Ionic bonds are formed by the complete transfer of electrons and covalent bonds are formed by sharing of electrons. The force between ionic bonds is electrostatic force, while that in covalent bonds is Van der Waals force. Generally, ionic bonds are much stronger than covalent bonds. In ionic bonds, there is a complete transfer of electrons between elements to form a stable compound. While in a covalent bond, there is only sharing of electrons between two elements to form a stable compound. The force that keeps the ions together is the electrostatic force and the force that keeps the elements together bonded with covalent bonds is the Van Der Waals force. As there is a complete transfer of electrons in ionic bonds, cations and anions are formed. Thus there exists a huge electrostatic force of attraction between these ions.