The process by which a metal, heated to high temperature, gives off electrons from its surface is known as

The process by which a metal, heated to a high temperature, gives off electrons from its surface is known as thermionic emission. When a metal is heated to a high temperature, some of its electrons gain enough energy to overcome the attractive forces of the metal atoms and are emitted from the surface of the metal. This process is known as thermionic emission, and the emitted electrons are called thermions. Thermionic emission is commonly used in vacuum tubes, such as cathode ray tubes and vacuum tubes used in radio and television equipment. In these devices, a metal filament is heated to a high temperature, causing the emission of electrons, which are then accelerated towards a positively charged electrode, producing an electric current. In summary, thermionic emission is the process by which a metal emits electrons from its surface when heated to a high temperature. It is commonly used in vacuum tubes for various electronic applications.