7: Equations

Question 1

energy carried by a photon (discrete packet of em radiation)

Answer 1

E = hf = hc / lambda

E = energy (joules)

h = planck’s constant (6.63 * 10^-34 Js)

c = speed of light

Question 2

Threshold frequency

Answer 2

f = Φ/h
where Φ = work function (J)
and h = Planck’s constant

Question 3

What is Φ?

Answer 3

The work function of a metal - it is the amount of energy required to remove an electron from the surface of the metal

Question 4

Maximum Kinetic Energy =

Answer 4

Ek = hf - Φ

Question 5

Relationship between probability and resultant phasor

Answer 5

Prob. ∝ (Resultant phasor)²

Question 6

equation with electronvolt, mass and velocity

Answer 6

eV = 1/2 mv²

Question 7

ways to write energy carried by a photon

Answer 7

E = hf = hc/lambda = eV0

Question 8

how to show change in energy between 2 energy levels

Answer 8

change in energy = E2 - E1 = hf = hc / lambda

Question 9

equation to work out frequency of phasor rotation

Answer 9

f = E / h

Question 10

de broglie equation

Answer 10

lambda = h / p = h / mv

Question 11

how to work out frequency for the phasor for an electron

Answer 11

f = Ekinetic / h
Ekinetic = 1/2 mv²