Why a positively charged atom want to gain electron?
Hi, Any atom tries to attain an octet configuration in its outermost orbit (to attain stability). For example, you will find that the most-inert elements (noble gases) have this octet configuration and hence are stable (however Helium is an exception). This is the reason why all other elements, having excess or a shortage of this octet configuration of electrons (in the outer orbit) tend to lose or attain electrons respectively (to become stable). When you speak of a positively charged atom (a positive ion), it means that this atom is trying to achieve stability by losing electrons (unless in case of processes where positive ions are formed by supplying energy externally). So this positive ion will remain stable unless it encounters an electron. When this interaction occurs, the ion is forced to combine with the free electron and attain its original state (due to the strong electrostatic forces that act between these unlike charges). That is why the ion combines with the electron, but
