Atoms and Ions: Electron Transfer Reactions

Atoms are the smallest units of an element, made up of protons, electrons and neutrons. The protons and neutrons are in the nucleus and the electrons orbit the nucleus.
Ions are atoms that have lost or gained electrons, giving them a positive or negative charge.
An electron transfer reaction is a type of chemical reaction where an electron moves from one atom to another.
These reactions can create ionic compounds. Ionic compounds consist of positive and negative ions joined together by electrostatic forces of attraction.
Electron transfer is a significant part of oxidation-reduction (redox) reactions. In these reactions, an electron (or electrons) transfers from an atom that becomes oxidised to another atom causing its reduction.
During redox reactions, the atom that loses the electron is known as the reducing agent, while the atom that gains the electron is known as the oxidising agent.
Iron rusting or burning of fuels are examples of real life redox reactions.
In terms of energy, these reactions are exothermic meaning they release energy, often in the form of heat or light.
The ability of an atom to attract and accept an electron is dependent on the type of element it is and its place in the periodic table. This is often measured by the electronegativity value.
Unsuitable conditions such as high temperatures or acidic environments can speed up redox reactions.
Electrolysis is a process that often involves electron transfer reactions. In this process, an electric current is passed through a substance to effect a chemical change.
Predicting the outcomes of these reactions involves understanding patterns in the periodic table, specifically the reactivity series of metals and the trend in reactivity of Group 7 elements.
Knowledge of electron transfer reactions can also support understanding of energy transfers and electrical circuits.