Ion

The nucleus of an atom is made up of positively charged protons and neutral neutrons, and it is surrounded by a cloud of negatively charged electrons. Electronically neutral atoms have the same number of protons and electrons. The atom has a net electrical charge if the total number of electrons does not equal the total number of protons.

An ion is any atom or molecule that has a net charge, either positive or negative. A monoatomic ion is made up of a single atom; a polyatomic ion is made up of two or more atoms. Because a proton’s positive electric charge is equal to an electron’s negative charge, an ion’s net electric charge is equal to its number of protons minus its number of electrons.

Ions are extremely reactive molecules. They are mostly found in a gaseous state and aren’t plentiful on Earth. When salts interact with their solvents in a liquid or solid state, ions are produced. Like electric charges repel them, while opposite charges attract them.

Type Of Ions

Ions come in a variety of shapes and sizes. Anions have a net negative charge because they have more electrons than protons. Cations have a net positive charge because they have more protons than electrons. Zwitterions are neutral molecules that have both positive and negative charges at different points. Because the surplus electrons resist each other and add to the physical size of the electron cloud, anions are often larger than the parent molecule or atom. Because of the reduced size of their electron clouds, cations are often smaller than their parent atoms or molecules.

This diagram depicts the interaction between a molecule, its cation, and its anion.

The net negative charge of an ion is written in superscript directly after the chemical structure of the atom/molecule. The magnitude of singly charged molecules/atoms is generally omitted when the net charge is written with the magnitude before the sign. Roman numerals are sometimes used to represent monoatomic ions, with the superscripted numerals denoting the net charge and the formal oxidation state of the element. Fe2+, for instance, can be referred to as Fe (II). For monoatomic ions, these representations are equivalent; however, Roman numerals cannot be used for polyatomic ions.

Forming Ions

Ionization is the process of a neutral atom losing or gaining electrons, which results in the formation of ions. The outer-shell electrons are more tightly bound to the positively charged nucleus and thus do not participate in this type of chemical interaction; the inner-shell electrons are more tightly bound to the positively charged nucleus and thus do not participate in this type of chemical interaction.

Ionization is the process of exchanging electrons between atoms or molecules. The process is motivated by the desire to achieve more stable electronic configurations, such as the octet rule, which states that the outermost (valence) shell of most stable atoms and ions has eight electrons. Polyatomic and molecular ions can also be formed by gaining or losing elemental ions in neutral molecules, such as H+. Polyatomic ions are notorious for being highly unstable and reactive.

Na+ is a common example of an ion. Because sodium possesses eleven electrons, it has a positive charge. Sodium, on the other hand, would be more stable with 10 electrons, according to the octet rule (2 in its innermost shell, 8 in its outermost shell). As a result, sodium loses an electron in order to become more stable. Chlorine, on the other hand, tends to gain one electron and form Cl–. Chlorine has 17 electrons by nature, however it would be more stable if it had 18 electrons (2 in its innermost shell, 8 in its second shell, and 8 in its valence shell). As a result, chlorine will get a negative charge by stealing an electron from another atom.

Conclusion 

We conclude that, when the amount of protons in an atom is not equal to the number of electrons, ions arise. If there are more protons than electrons, the ion is referred to as a cation; if there are more electrons, the ion is referred to as an anion.

Ions are extremely reactive molecules. They are mostly found in a gaseous state and aren’t plentiful on Earth. Like electric charges repel them, while opposing charges attract them.

The size of an atom is determined by its electron cloud; more electrons (anions) enhance electron repulsion, resulting in a larger ion, whereas cations (with fewer electrons) are smaller than the atom because there are fewer electrons in the cloud to reject each other.