The term for valence electrons in a molecule that are shared between two or more atoms is called "shared electrons" or "bonding electrons." These electrons participate in chemical bonds, forming covalent bonds between atoms.
Covalent bonding occurs when atoms share electrons to achieve a more stable electron configuration. Each atom contributes one or more electrons to the shared electron pair, forming a shared cloud of electrons that is localized between the atoms.
These shared electrons are responsible for holding the atoms together in a molecule and determine the strength and nature of the chemical bond. The number and arrangement of shared electrons in a molecule influence its structure, properties, and chemical reactivity.