What type of bond is formed when two atoms share electrons?

The formation of a covalent bond occurs when two atoms share electrons to achieve greater stability, particularly to attain a full outer electron shell, which is a key characteristic of noble gases. This type of bonding is common among nonmetals, allowing them to form molecules that can exhibit low melting points and varying states of matter (solid, liquid, gas) at room temperature. The shared electrons in a covalent bond create a strong connection that holds the atoms together, making it a fundamental concept in chemistry for understanding molecular structures and reactions.

In contrast, an ionic bond involves the complete transfer of electrons from one atom to another, resulting in the formation of charged ions. Metallic bonds, on the other hand, are characterized by a "sea of electrons" that are free to move around metal cations, which isn't relevant to the sharing of electrons between two atoms. Lastly, hydrogen bonds are a type of weak intermolecular attraction that occurs between polar molecules, not a bond formed by sharing electrons between atoms. Understanding these differences further highlights the unique nature of covalent bonds in chemical interactions.