Quantum Physics

Question 1

What are mesons made up of?

Answer 1

quark+antiquark pair

Question 2

What do Feynman diagrams represent?

Answer 2

…the interaction between 2 particles or antiparticles. OR, the decay of a particle and an antiparticle.

Question 3

What are Baryons and antibaryons?

Answer 3

… they are hadrons that consist of 3 quarks for a baryon or 3 antiquaks for an antibaryon.

Question 4

Define threshold frequency (JR)

Answer 4

The minimum frequency required to cause the photoelectric effect

Question 5

What is the work function? (JR)

Answer 5

The minimum energy required to free an electron from the surface of a metal

Question 6

Describe the photoelectric effect (JR)

Answer 6

Emission of electrons from the surface of a metal when it is illuminated by light with a frequency greater than the threshold frequency.

Question 7

What is the maximum kinetic energy of a photoelectron? (BRT)

Answer 7

hf - @ or (photon energy - work function)

Question 8

What does the de Broglie hypothesis state?

BRT

Answer 8

That matter particles have a wave-like nature characterised by the de Broglie wavelength.

Question 9

What happens to a conduction electron when it absorbs a single quantum of light below the threshold frequency? (BRT)

Answer 9

It absorbs the photon and gains its energy as K.E. which is very quickly lost as the electron collides with other electrons and positive ions.