Full electron shells are considered stable because they have achieved a state of maximum energy efficiency. This means that all the electrons in the shell are in their lowest possible energy state, making them less likely to react with other atoms and form chemical bonds.
Having a full electron shell decreases an atom's reactivity because it is energetically unfavorable for it to gain or lose electrons. This makes it less likely for the atom to form chemical bonds with other atoms.
The stability of an electron shell is determined by the number of electrons it contains. If the shell is full, it is considered stable. However, if the shell is not full, the atom will try to gain or lose electrons in order to achieve a full shell and become more stable.
Atoms strive to have full electron shells because it allows them to achieve a lower energy state, making them more stable. This is because full electron shells follow the octet rule, which states that atoms are most stable when they have 8 electrons in their outermost shell.
No, full electron shells are not always considered stable. Some elements, such as the noble gases, have full electron shells but are still very reactive due to their high ionization energies. This means that it requires a lot of energy to remove an electron from these atoms, making them less likely to form chemical bonds.