12 - Quantum Physics

Question 1

particle model

Answer 1

Particles that are hard, have mass and move according to the laws of Newtonian mechanics

Question 2

Wave model

Answer 2

Shaped like a sine graph, do not have mass or charge, their defining characteristics are diffraction and interference.

Question 3

Photoelectric effect

Answer 3

When an electromagnetic radiation of sufficiently high frequency falls on a metal surface, electrons are emitted

Question 4

Photoelectric current

Answer 4

current due to photo-electrons

Question 5

First law of photoelectric emission

Answer 5

Number of photo-electrons emitted per second is directly proportional to the intensity of incident radiation

Question 6

second law of photoelectric emission

Answer 6

Maximum kinetic energy of photo-electrons is directly proportional to frequency of the incident radiation, but independent of is intensity.

Question 7

third law of photoelectric radiation

Answer 7

for every metal, there is a minimum frequency of incident radiation below which photoelectric emission does not take place. (threshold frequency)

Question 8

threshold frequency

Answer 8

Minimum frequency required to release electrons from the surface of a metal.

Question 9

Photon

Answer 9

Each quantum of electromagnetic radiation

Question 10

Work function

Answer 10

Minimum amount of energy required by an electron to escape the surface

Question 11

Emission line spectra

Answer 11

The composition of light emitted by a hot gas

Question 12

Absorption line spectra

Answer 12

When white light is passed through a cool gas