What is the role of electrons in chemical bonding?

Electrons play a crucial role in chemical bonding by either being shared or transferred between atoms.

In more detail, chemical bonds are the forces that hold atoms together in molecules and compounds. These bonds form because atoms seek to achieve a stable electron configuration, often resembling the nearest noble gas with a full outer shell of electrons. There are two main types of chemical bonds: covalent and ionic.

In covalent bonding, atoms share pairs of electrons. This usually happens between non-metal atoms. For example, in a water molecule (H₂O), each hydrogen atom shares an electron with the oxygen atom, allowing all involved atoms to achieve a more stable electron arrangement. The shared electrons create a strong bond that holds the atoms together.

On the other hand, ionic bonding involves the transfer of electrons from one atom to another, typically between a metal and a non-metal. For instance, in sodium chloride (NaCl), a sodium atom donates an electron to a chlorine atom. This transfer creates positively charged sodium ions (Na⁺) and negatively charged chloride ions (Cl⁻). The opposite charges attract each other, forming a strong ionic bond.

Electrons in the outermost shell, known as valence electrons, are the ones involved in bonding. The number of valence electrons determines an element's chemical properties and its ability to bond with other elements. For example, carbon has four valence electrons, allowing it to form up to four covalent bonds with other atoms, making it incredibly versatile in forming complex molecules.

Understanding the role of electrons in chemical bonding helps explain why substances have different properties, such as melting points, electrical conductivity, and solubility. By analysing how electrons are shared or transferred, we can predict and explain the behaviour of different materials in various chemical reactions.