Which type of bond forms when two atoms share electrons?

The type of bond that forms when two atoms share electrons is known as a covalent bond. In a covalent bond, the atoms involved typically have similar electronegativities, which allows them to share pairs of electrons rather than transferring them. This sharing enables each atom to attain a more stable electron configuration, much like that of a noble gas.

Covalent bonding is the foundational concept for many organic and inorganic compounds. It plays a critical role in the formation of molecules such as water (H₂O), where hydrogen and oxygen share electrons, creating a stable compound.

In contrast, ionic bonds involve the transfer of electrons from one atom to another, usually between a metal and a nonmetal, resulting in the formation of charged ions. Hydrogen bonds are weak attractions that occur between polar molecules, and metallic bonds involve a "sea of electrons," which allows metal atoms to share their electrons freely in a lattice structure. Hence, the characteristics of covalent bonding make it distinct and particularly important for the chemistry of life and the formation of diverse substances.