Rutherford Scattering

Atomic Physics · 1911

Equation: dσ/dΩ = (Z₁Z₂e²/16πε₀E)² / sin⁴(θ/2)
Field: Atomic Physics
Named After: Ernest Rutherford
Year: 1911

Symbols

dσ/dΩ how many particles scatter into each direction · Z₁, Z₂ charges of projectile and target nucleus · E projectile energy · θ scattering angle · the sin⁴ makes large-angle bounces rare but real

Significance

Fire alpha particles at gold foil and a few come straight back — 'as if you fired a shell at tissue paper and it bounced.' Only a tiny, dense, charged nucleus could do that: the atom is mostly empty space. Coulomb's law, applied one nucleus at a time, and the birth of the nuclear atom.