2.2 Bonding

Now that you have a better idea of how electrons behave in atoms, what orbitals are, and how electrons occupy them we can begin to look at what happens when atoms interact with each to form molecules and chemical bonds.

You will have previously encountered the Van Arkel–Ketelaar triangle, which compares the three main types of bonding: covalent, ionic and metallic. What dictates which bonding type will be adopted is the electronegativity of the atoms in the bond. Electronegativity is the ability of an atom to attract electrons.

Elements on the bottom-left side of the periodic table are less electronegative or more electropositive, meaning they very weakly attract the electrons of other atoms towards themselves, while they very easily give up their own electrons. Conversely, elements towards the top-right of the periodic table are more electronegative; strongly attracting electrons from other atoms and strongly withholding their own electrons.