What occurs when an atom’s valence shell is filled with electrons?

When an atom's valence shell is filled with electrons, it becomes stable. The stability of an atom is closely linked to the arrangement of its electrons, particularly in the outermost shell, known as the valence shell. Atoms tend to seek stability by achieving a full valence shell, which corresponds to a lower energy state. For many elements, this full shell corresponds to having eight electrons, known as the octet rule, although there are exceptions.

Atoms usually achieve a full valence shell through various means such as sharing electrons (covalent bonds), transferring electrons (ionic bonds), or participating in metallic bonding. When the valence shell is filled, the atom is less likely to engage in chemical reactions because it has a configuration that satisfies its energy requirements. This stability is why noble gases, which naturally have filled valence shells, are found at the far right of the periodic table and are generally inert, meaning they do not readily react with other elements.

As for the other options, becoming a gas or a liquid does not directly relate to the filling of the valence shell. Physical states depend on numerous factors, including temperature and pressure, rather than the electronic configuration. Gaining a positive charge would imply the loss of electrons, which