Dual Nature of Radiation and Matter

Vocabulary flashcards covering the introduction to the dual nature of light, photon properties, and types of electron emission based on the lecture notes.

Wave nature of light

Established by Maxwell's equations of electromagnetism and Hertz experiment during the generation and detection of electromagnetic waves.

Particle nature of light

Proven by the discoveries of the photoelectric effect by Heinrich Hertz and the Compton effect by A.H. Compton.

Compton effect

The scattering of $X$-rays from electrons which demonstrates the particle nature of light.

Photon

A quantum of light that is electrically neutral, massless, and not deflected by electric or magnetic fields.

Photon Energy ($E$)

The energy of a photon calculated as $E = h\nu$ or $E = \frac{hc}{\nu}$, which depends on frequency but is independent of intensity.

Photon Momentum ($P$)

The momentum of a photon expressed by the formula $P = \frac{h}{\nu}$.

Thermionic emission

The phenomenon of electron emission from a metal surface when heated suitably, such as the Edison effect.

Field emission

The phenomenon of electron emission from a metal surface under the application of a strong electric field, such as in a spark plug.

Photoelectric emission

The phenomenon of electron emission from a metal surface when radiations of suitable frequency fall on it.

Hertz’s observation (1887)

While studying electromagnetic waves, Heinrich Hertz noticed that ultraviolet light shining on a metal electrode allowed sparks to jump across the gap more easily, indicating easier electron escape.