When atoms form chemical bonds, they share or exchange electrons to become stable. Atoms are most stable when they have a full outermost shell of electrons. The octet rule says that atoms tend to gain, lose, or share electrons to have 8 electrons in their outermost shell because that's a very stable configuration.
The octet rule is based on observations of how different elements behave and how their electrons are arranged. However, there are exceptions to this rule, and scientists are still studying why certain atoms can have more than 8 electrons in their outermost shell and still be stable.
joshuatyberg t1_j99sg8m wrote
Reply to ELI5: How do we know for certain that atoms can't have more than 8 maximum outermost electrons when atoms form chemical bonds? Is there any research being done to see why atoms prefer the octet rule? by ArcadeAndrew115
When atoms form chemical bonds, they share or exchange electrons to become stable. Atoms are most stable when they have a full outermost shell of electrons. The octet rule says that atoms tend to gain, lose, or share electrons to have 8 electrons in their outermost shell because that's a very stable configuration.
The octet rule is based on observations of how different elements behave and how their electrons are arranged. However, there are exceptions to this rule, and scientists are still studying why certain atoms can have more than 8 electrons in their outermost shell and still be stable.