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

When two atoms come together and share electrons, they form a covalent bond. This type of bond occurs when the atoms involved have similar electronegativities, meaning they have a comparable ability to attract electrons. By sharing electrons, each atom can achieve a more stable electron configuration, often resembling that of the nearest noble gas, which has a complete outer shell of electrons.

Covalent bonds can result in the formation of molecules, such as water (H2O) or carbon dioxide (CO2), where the shared electrons allow the atoms to remain bonded together. This sharing can occur in different forms, including single, double, or triple bonds, depending on the number of electron pairs shared between the atoms.

In contrast, an ionic bond is formed through the transfer of electrons from one atom to another, leading to the formation of charged ions. Hydrogen bonds, although important in biological systems and molecular interactions, are generally weaker interactions that occur between molecules due to partial positive and negative charges. Metallic bonds involve the pooling and sharing of electrons among a lattice of metal atoms, allowing for properties like conductivity and malleability.