Quantum Physics Flashcards
1
Q
What is the photon model of electromagnetic radiation?
A
Electromagnetic radiation can be thought of as little packets of energy, rather than a continuous wave.
2
Q
What is the energy of a photon?
A
The frequency of the EM radiation x the Planck constant (k).
3
Q
What is 1 electron volt in Joules?
A
1.6x10^-19 J
4
Q
What is the photoelectric effect?
A
When electromagnetic radiation incident on a metal surface is absorbed and causes electrons to be emitted.
5
Q
What experiment gives evidence for the photoelectric effect?
A
Shining UV light onto a zinc plate in a gold leaf electroscope causes the gold leaves to become charged and stick together.
6
Q
How does the photoelectric effect provide evidence for the photon nature of light? (3 things)
A
- Electrons are emitted only if the incident light is above a certain threshold frequency. (Independent of intensity).
- Electrons are emitted instantly above the threshold frequency.
- Increasing the intensity of the incident light increases the number of electrons emitted, not their KE.
