State what the term photon means.
State the name of the phenomenon in which electrons are emitted from the surface of a metal plate when electromagnetic radiation shines on it.
The phenomenon is seen only when the frequency of the electromagnetic radiation is above a certain minimum value, regardless of the intensity of the radiation. Explain how this observation gives evidence for the existence of photons.
State the name of the quantity shown by the gradient of the line in Fig. 8.1.
State the name of the quantity shown by the $y$-intercept of the extrapolated line in Fig. 8.1.
State the name of the quantity shown by the gradient of the line in Fig. 8.1.
State the name of the quantity shown by the $y$-intercept of the extrapolated line in Fig. 8.1.