Learn: Quantum Physics and Particle Theory

Photon energy formula

E = hf = hc/λ

Planck constant value

6.63 × 10⁻³⁴ J s

Electronvolt (eV) value

1.60 × 10⁻¹⁹ J

LED threshold voltage equation

eV = hc/λ

Threshold frequency

Minimum frequency required to emit electrons from a metal surface.

Einstein's photoelectric equation

hf = φ + KE_max

Work function (φ)

Minimum energy needed to free an electron from a metal surface.

Photoelectron kinetic energy dependency

Depends only on the frequency of the incident light.

Effect of increasing light intensity

Increases photoelectron emission rate without changing maximum kinetic energy.

Gold-leaf electroscope demonstration

Shows photoelectric emission using UV light on a zinc plate.

Electron diffraction evidence

Proves electrons exhibit wave-like behavior through atomic lattices.

De Broglie equation

λ = h/p

Antiparticle definition

Particle with identical mass but opposite charge.

Positron

The positively charged antiparticle of the electron.

Hadrons

Particles subject to the strong nuclear force.

Leptons

Particles that do not experience the strong nuclear force.

Quark flavours

Up (u), down (d), and strange (s).

Up quark charge

+⅔e

Down quark charge

−⅓e

Strange quark charge

−⅓e

Proton quark composition

uud

Neutron quark composition

udd