Question

List four conditions that may result in the emission of electrons from a conductor

Answer 1

Conditions that result in the emission of electrons from a conductor:

Heating the conductor to a suitable temperature

Exposing the conductor to a strong light

Subjecting the conductor to a very high applied voltage

Subjecting the conductor to high-speed electrons from another source

Step-by-step explanation:

Answer 2

There are 4 ways in which electrons are emitted from the conductor.

i. Thermionic emission

ii. Electric field electron emission

iii. Photoelectric emission

iv. Secondary emission

In thermionic emission large amount of external energy in the form of heat is supplied to release free electrons from the metal.

In electric field electron emission, electrons are emitted from the metal surface when the metals are placed in a very strong electric field.

During photoelectric emission, light is absorbed by the metals and this provides energy to the valence electrons which break their bond with the parent atom and which are then released from the atom.

Valence electrons do have some kinetic energy, but they don't have enough energy to escape from the atom. During secondary emission, a high-speed electron is bombarded with an atom, which provides the energy for the valence electrons to break their bonds with their parent atom which are then released from the atom.