Chapter 12.1

Question 1

Quantum

Answer 1

A bundle of light

Question 2

Formulas for momentum of photons

Answer 2

p = E/c = hf/c = h/λ

Question 3

Photoelectric effect

Answer 3

The phenomenon in which light incident on a metallic surface causes electrons to be emitted from the surface

Question 4

Photo-surface

Answer 4

The metallic surface that light is incident on

Question 5

Stopping voltage

Answer 5

The voltage at which the current in a device investigating the photoelectric effect becomes zero

Question 6

Why is the stopping voltage in the photoelectric effect significant?

Answer 6

Gives the maximum kinetic energy of emitted electrons, eVs

Question 7

True or false? Stopping voltage is dependent of the intensity of the light source

Answer 7

False. Stopping voltage is independent of intensity

Question 8

Four observations from photoelectric effect experiment

Answer 8

1. The intensity of light does not affect the energy of the emitted electrons
2. The electron energy depends on the frequency of the incident light
3. There is a certain minimum frequency below which no electrons are emitted
4. Electrons are emitted with no time delay

Question 9

Quanta

Answer 9

Bundles of energy and momentum

Question 10

Formula for energy of a quantum

Answer 10

E = hf

h = 6.63 x 10^(-34)

Question 11

Work function

Answer 11

The amount of energy an electron spends to free itself from the pull of the nuclei of the atoms of a photo-surface

Question 12

Formula for maximum kinetic energy of an electron emitted from a photo-surface

Answer 12

Emax = hf - Φ

Question 13

Pair annihilation

Answer 13

The process where a particle collides with an anti-particle and forms two photons

Question 14

Pair creation

Answer 14

When a single photon is produced in the presence of a nucleus from pair annihilation

Question 15

Formula for longest wavelength of particles emitted from particle annihilation

Answer 15

λ = (hc)/(mc^2)

Question 16

Angular momentum formula

Answer 16

mvr = (nh)/(2π)

Question 17

Formula for electron energy in a hydrogen atom

Answer 17

E = -13.6/n^2 eV

Question 18

Wavefunction

Answer 18

The wave in Schrödinger’s theory, which is a function of position and time

Question 19

Heisenberg uncertainty principle

Answer 19

It is not possible to measure simultaneously the position and momentum of a particle with indefinite precision

Question 20

Heisenberg formula for finding uncertainty in position and momentum

Answer 20

∆x∆p ≥ h/4π

Question 21

Heisenberg formula for finding uncertainty of energy and time

Answer 21

∆E∆t ≥ h/4π

Question 22

Three factors that affect probability of tunneling

Answer 22

Mass of particle
Width of barrier
∆E between barrier and particle