Ion

History and Characteristics of Ions:
– The term ‘ion’ originated from the Greek word meaning ‘to go’.
– Cation and anion terms were introduced by Michael Faraday in 1834.
– Svante Arrhenius explained salt dissociation into ions in 1884.
– Faraday coined words like anode, cathode, anion, and cation.
– Arrhenius proposed that ions can form even without electric current.
– Ions in the gas state are highly reactive.
– Solvated ions in liquid or solid states are more stable.
– Anions are larger than parent molecules, while cations are smaller.
– Anions have more electrons than protons, giving them a negative charge.
– Cations have fewer electrons than protons, giving them a positive charge.

Natural Occurrences and Applications of Ions:
– Ions are found in diverse natural phenomena.
– Ions contribute to the Sun’s luminescence and Earth’s ionosphere.
– Interaction of water and ions is crucial in chemistry and biochemistry.
– Ions play a role in energy production like ATP breakdown.
– Ions are essential for various technological applications like ion engines and mass spectrometers.

Detection of Ionizing Radiation:
– Ionization events in gas detect radiation types like alpha, beta, gamma, and X-rays.
– Various devices like ion chambers, Geiger-Müller tubes, and proportional counters are used for detecting ionizing radiation.
– Free electrons release further electrons by ion impact.

Chemistry and Formation of Ions:
– Ions are formed by gaining or losing electrons to the valence shell.
– Ionization potential is the energy required to detach an electron from an atom.
– Metals generally have lower ionization energy than nonmetals.
– Ionic bonding occurs through mutual attraction of oppositely charged ions.
– Formation of monatomic, polyatomic, and molecular ions involves gaining or losing elemental ions.

Naming and Classification of Ions:
– Cations are positively charged ions, anions are negatively charged ions.
– Different classes of ions include radical ions, oxyanions, organic ions, carbocations, and carbanions.
– Net charge on ions is denoted in superscript after the chemical structure.
– Ions with unpaired electrons are known as radical ions.
– Formation of complex ions may involve mixed Roman numerals and charge notations.

Ion (Wikipedia)

For other uses, see Ion (disambiguation).

An ion (/ˈaɪ.ɒn, -ən/) is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons.

A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds.

Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. Ions are also created by chemical interactions, such as the dissolution of a salt in liquids, or by other means, such as passing a direct current through a conducting solution, dissolving an anode via ionization.