EVERYDAY SCIENCE

Detailed explanation-1: -If the stability of the atom increases, its reactivity will decrease. Therefore, the atoms with a complete octet and noble gas configuration will have higher stability and less reactivity. The atoms that have an incomplete octet are less stable and more reactive.

Detailed explanation-2: -Electrons in the outermost energy level of an atom have a special significance. These electrons are called valence electrons, and they determine many of the properties of an atom. An atom is most stable if its outermost energy level contains as many electrons as it can hold.

Detailed explanation-3: -A full valence shell is the most stable electron configuration. Elements in other groups have partially filled valence shells and gain or lose electrons to achieve a stable electron configuration.

Detailed explanation-4: -In general, atoms are most stable, least reactive, when their outermost electron shell is full. Most of the elements important in biology need eight electrons in their outermost shell in order to be stable, and this rule of thumb is known as the octet rule.