What type of bond is formed when atoms share electrons?

The formation of a covalent bond occurs when two or more atoms share electrons, allowing them to achieve greater stability by filling their outer electron shells. This type of bond typically forms between non-metal atoms. For instance, in a water molecule, the oxygen atom shares electrons with two hydrogen atoms, creating strong covalent bonds that hold the molecule together. The result is a stable chemical compound where each atom involved benefits from the shared electrons, leading to lower energy states and increased stability.

In contrast, ionic bonds form when electrons are transferred from one atom to another, leading to the attraction between oppositely charged ions. Metallic bonds involve a 'sea of electrons' that are shared among many metal atoms, resulting in conductivity and malleability. Hydrogen bonds, while important in biological systems, are relatively weak interactions that occur due to the attraction between a hydrogen atom covalently bonded to a more electronegative atom and another electronegative atom.

This understanding of covalent bonds establishes their critical role in forming stable compounds through electron sharing, which distinguishes them from other types of chemical bonds.