# 7: Equations Flashcards

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

E = hf = hc / lambda

E = energy (joules)

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

c = speed of light

Threshold frequency

f = Φ/h

where Φ = work function (J)

and h = Planck’s constant

What is Φ?

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

Maximum Kinetic Energy =

Ek = hf - Φ

Relationship between probability and resultant phasor

Prob. ∝ (Resultant phasor)²

equation with electronvolt, mass and velocity

eV = 1/2 mv²

ways to write energy carried by a photon

E = hf = hc/lambda = eV0

how to show change in energy between 2 energy levels

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

equation to work out frequency of phasor rotation

f = E / h

de broglie equation

lambda = h / p = h / mv

how to work out frequency for the phasor for an electron

f = Ekinetic / h Ekinetic = 1/2 mv²