Can you predict what happens to the atoms that already have eight electrons in their outermost shell (except the elements with one shell only, where only two electrons are possible)? Will they still try to lose or gain electrons?
Atoms that already have eight electrons in their outermost shell possess a complete octet. In the case of elements with only one shell, having two electrons also makes the valence shell complete. It has been observed that elements with such complete valence shells are largely unreactive and more stable.
Because their outermost shell is already full, these atoms have no tendency to alter their electron count. Therefore, they will not try to lose, gain, or share electrons. Only atoms with incomplete valence shells are usually more reactive and undergo electron transfer to complete their octet.
Explanation
The textbook context explicitly states that an outermost shell with 8 electrons is called an octet. Elements with a complete octet (or 2 electrons in the first shell, like helium) are largely unreactive and stable. Because they are already stable, they do not need to lose, gain, or share electrons, unlike atoms with incomplete valence shells which are reactive.
Solution Steps
Step 1: Identify that 8 electrons in the outermost shell form a complete octet.
Step 2: Note that elements with a complete octet are stable and unreactive.
Step 3: Conclude that such atoms will not try to lose, gain, or share electrons.