How does an element like sodium give up electrons and thereby become more stable?

Answer 1

Atoms want their valence orbitals to be completely filled with electrons. In the case of a sodium atom, there is only 1 electron in its outer orbital. Since sodium has electrons occupying all the molecular orbitals of the previous n shell, it is much easier to just give up the electron and form a complete orbital rather than obtain 7 more electrons to complete the orbital. In addition this would require the ion be a charge of negative 7 which is highly unstable in its own right.

In the case of lithium hydrogen and helium, 2 electrons may fill the 1s orbital which is considered to be a full valence shell, lithium will lose an electron to gain the full 1s which hydrogen will gain an electron to fill its 1s orbital and helium will remain inert with the already required 2 electrons filling its 1s orbital.

Answer 2

Sodium, like other alkali metals, has one outer electron that is easily lost to achieve a stable electron configuration. When sodium reacts, it donates this electron to another atom, usually a nonmetal like chlorine, forming an ionic bond. By giving up its outer electron, sodium achieves a full outer shell electron configuration, becoming more stable in the process.