Final answer:
A bond where two elements share electrons is known as a covalent bond, which can be either nonpolar if the sharing is equal or polar if the sharing is unequal due to differences in electronegativity.
Step-by-step explanation:
When two elements are willing to share electrons rather than transferring them completely, the type of bond that forms is called a covalent bond. This bonding occurs when neither atom is willing to relinquish control over its valence electrons, leading them to occupy a space between the nuclei of both atoms. This creates a stable molecular structure.
The sharing of electrons can result in either nonpolar or polar covalent bonds. A nonpolar covalent bond occurs when the atoms involved share the electrons equally, such as in the molecule of molecular oxygen (O₂). However, polar covalent bonds form when there is an inequality in the sharing due to differences in electronegativity between the two atoms. For example, in a water molecule, the bond between hydrogen and oxygen is polar because oxygen, being more electronegative, pulls the shared electrons closer to itself.