Atoms have a certain number of electrons in their outermost shell, and this number determines the type of chemical bonds they can form. We know that atoms can't have more than 8 maximum outermost electrons because of the octet rule. This rule states that atoms will always try to fill their outermost shell with 8 electrons in order to achieve a stable electron configuration. This is why atoms prefer to form chemical bonds with other atoms that will give them 8 electrons in their outermost shell. Research is being done to understand why atoms prefer the octet rule. Scientists are studying the electronic structure of atoms and molecules to understand why the octet rule is so important for chemical bonding.