What are X-Rays

Question 1

Travelling waves satisfy a differential equation called the

Answer 1

linear wave equation

Question 2

Order from lowest to highest amt of radiation

Answer 2

radio waves, microwaves, infrared, visible light, UV, XRay, gamma

Question 3

Speed of light

Answer 3

c=3x10^8 m/s

Question 4

Energy

Answer 4

E=hf=hc/λ

Question 5

Plancks constant

Answer 5

h=6.62x10^-34

Question 6

(photoelectric effect) current reaches max value when

Answer 6

all the ejected electrons from plate A reach plate B. it does not increase past this saturation point even if V is increased

Question 7

(photoelectric effect) if V is decreased to 0

Answer 7

there are still enough electrons with enough kinetic energy to go from plate A to B

Question 8

(photoelectric effect) Stopping potential

Answer 8

to reduce the current to 0, the potential difference must be reversed to the value Vs

Question 9

KEmax=eVs

Answer 9

the kinetic energy of the fastest ejected electrons

Question 10

max KE is ______ of the intensity of the incident light

Answer 10

independent

Question 11

stopping potential ______ with increasing incident light frequency

Answer 11

increases, maximum KE of ejected electrons increases with frequency

Question 12

wave theory: oscillating vector E will increase

Answer 12

as intensity of light increases

Question 13

wave theory predicts the photoelectric effect should

Answer 13

occur for any frequency of light if it is intense enough to eject the electron (not the case because cut off frequency)

Question 14

if the light intensity were to be weak and we assume the energy is absorbed over the wave front

Answer 14

it should take time to absorb enough energy for electron to be ejected (no time lag)

Question 15

Quantum theory

Answer 15

• energy is in bundles of photons
• each bundle moves with velocity c
• energy of bundle is related to frequency
• energy is absorbed by electron: max KE=hf-w0

Question 16

(quantum theory) doubling the intensity of light

Answer 16

doubles the amount of photons, increasing emitted electrons, does not change the energy (hf) of individual electrons

Question 17

(quantum theory) when the kinetic energy of the electron is 0

Answer 17

there is just enough energy to liberate the electron but none to give it kinetic energy. if it is reduced any further there is not enough energy to overcome the work function no matter how many photons

Question 18

(quantum theory) energy is concentrated in bundles not a wave front thus it only take 1 photon to

Answer 18

be absorbed to immediately eject an electron

Question 19

electromagnetic radiation has properties…

Answer 19

of a particle and a wave

Question 20

who postulated that this wave particle behaviour should apply to matter?

Answer 20

louise de broglie

Question 21

a particle will have an associated

Answer 21

matter wave

Question 22

energy is related to

Answer 22

frequency, and momentum p is related to wavelength p=h/λ