All About Electronic Configurations of Cations and Anions

An anion is a negatively charged ion, whereas a cation is a positively charged ion. In chemistry, ionisation is defined as any process that results in the breakdown of a neutral atom or molecule into negatively charged particles (ions). An anion is an ion that is negatively charged, as opposed to a cation.

Cations and Anions

Cations and Anions are formed by the reaction of Neutral Atoms. Every atom in its ground state has no charge attached to it. It has the same number of protons and electrons as it does protons and electrons, according to its atomic number. Electrons, on the other hand, are extremely labile, and an atom will frequently gain or lose electrons based on its electronegativity. It is the energetically ideal state of having a full valence (outermost) shell of electrons that serves as the driving force for such gain or loss of electrons. Consequently, the charged atom formed has the electron configuration of a noble gas when this condition is met.

Monatomic Ions are formed during the course of a reaction.

In chemistry, monatomic ions are generated by the addition or removal of electrons from the shell of an atom’s valence. In an atom, the inner shells are occupied by electrons that are strongly linked to the positively charged atomic nucleus and do not participate in this type of chemical interaction. However, the valence shell, depending on the atom and its electron configuration, can be extremely reactive. When an atom or molecule becomes ionised, it means it has gained or lost electrons from being a neutral atom or molecule.

In addition to bombardment with radiation, the transfer of electrons between atoms and molecules is the more pure chemical process of ionisation. The stabilisation that occurs as a result of attaining stable (full shell) electrical setups is the driving force behind this transfer. Atoms will gain or lose electrons based on which activity requires the least amount of energy to complete.

The element sodium (Na) belongs to the Group 1 element family and has a single electron in its valence shell, with complete shells of two and eight electrons beneath. Because of the removal of this one electron, sodium is no longer unstable: The sodium atom now has eight electrons in its outermost shell, giving it the electron configuration of a neon atom. Because it has acquired a positive charge, the sodium ion is referred to as a cation. 

The element sodium has the ability to gain electrons, but it would require another seven to establish a complete valence shell. Because removing one electron is significantly easier than acquiring seven, sodium will always attain its octet by converting to a cation in any given chemical scenario, regardless of the circumstances.

Instead, the chlorine atom (Cl) has seven electrons in its valence shell, one less than a stable, full shell of eight electrons, which is the case for the oxygen atom (O). A chlorine atom will tend to gain an extra electron and achieve a stable 8-electron configuration (the same as that of argon).

The ability of sodium to lose an electron in combination with the ability of chloride to receive an electron results in complementary reactivity, as demonstrated by the following equation: When the uncharged atoms are joined, they can interchange electrons and, as a result, achieve complete valence shell formation. The resultant ions are held together by ionic bonds (opposite charges attract), resulting in the formation of a crystal lattice structure of sodium chloride (NaCl), which is more widely known as rock salt. The following is how people reacted:

Na+ + Cl– →  NaCl.

Ions of Polyatomic and Molecular Structure

Ionisation is not restricted to the formation of single atoms; polyatomic ions can also be produced. In neutral molecules, the addition or removal of elemental ions such as H+ frequently results in the formation of polyatomic and molecular ions. Example: When the ion ammonia (NH3) absorbs a proton (H+), it produces the ammonium ion (NH4+) in the presence of the proton. A net positive charge is imparted to ammonium by the presence of an additional proton (the H+), whereas ammonia has a net negative charge due to the presence of the same amount of electrons in basically the same electronic configuration.

Conclusion 

Therefore it can be concluded, The addition of an electron will cause the proton-electron equilibrium to be upset, resulting in the atom becoming negatively charged. The removal of an electron, on the other hand, will leave the atom with a positive charge. Ions are atoms that have been charged with a positive charge.