Final answer:
In chemical bonding, electrons, especially valence electrons, are the subatomic particles that are most significant. Covalent bonds involve shared valence electrons and their strength depends on orbital overlap and electronegativity differences, while ionic bonds result from electron transfer between atoms.
Step-by-step explanation:
The subatomic particles that play the biggest role in bonding are electrons, particularly those in the outermost electron shell, known as valence electrons. Chemical bonding involves the interaction of valence electrons between atoms. Covalent bonds are formed when atoms share valence electrons, with the bond strength governed by the overlap of atomic orbitals and the electronegativity difference between the atoms involved. On the other hand, ionic bonds occur when there's a complete transfer of electrons from one atom to another, leading to the formation of oppositely charged ions that attract each other. The stability of a molecule, such as that of iron, is determined by binding energy, with iron requiring the most energy to break down due to its high binding energy at its optimal nuclear mass.
Factors influencing bond strength and stability include orbital overlap, electronegativity differences, and partial charges within the molecular structure. For example, in a molecule with a polar covalent bond, such as HF (hydrogen fluoride), the difference in electronegativity leads to an uneven sharing of electrons, causing a greater bond moment. The spatial arrangement of electron regions, determined by repulsions between different types of electron pairs or bonds, also plays a critical role in the molecular geometry and ultimately in the bonding interactions.