Electron Emission

The video tutorial explains the concept of free electrons in metals and their role in conductivity. It introduces the work function, the minimum energy required for an electron to escape a metal, and how it is measured in electron volts. The tutorial also covers three processes of electron emission: thermionic emission, field emission, and photoelectric emission, detailing how electrons gain energy to leave the metal surface in each process.

What prevents free electrons in metals from leaving the surface?

• The repulsive force of other electrons

• The attractive force of the nucleus

• The magnetic field of the metal

• The gravitational pull of the Earth

What is the unit of measurement for the work function of a metal?

• Newtons

• Watts

• Electron volts

• Joules

Which factor does NOT affect the work function of a metal?

• Presence of an electric field

• Surface impurities

• Temperature of the environment

• Nature of the metal

In which process do electrons gain energy from heat to leave a metal surface?

• Chemical emission

• Thermionic emission

• Photoelectric emission

• Field emission

What is the term for electrons emitted when light hits a metal surface?

• Lightons

• Field electrons

• Photoelectrons

• Thermions