Lesson 11.5: Quantum Mechanics (wavefunctions, uncertainty principle) - Summary
Key Concepts: Quantum Mechanics
Key Principles
- Wave-Particle Duality: All matter exhibits both wave and particle properties. λ = h/p.
- Quantization: Energy, angular momentum, and other properties come in discrete amounts.
The Wavefunction (ψ)
- The wavefunction describes the quantum state of a particle.
- |ψ|² gives the probability density of finding the particle at a given position.
- The wavefunction evolves according to the Schrödinger equation.
Heisenberg's Uncertainty Principle
- It is impossible to simultaneously know both the exact position and momentum of a particle:
- Δx · Δp ≥ ℏ/2 (where ℏ = h/2π).
- This is not a measurement limitation — it's a fundamental property of nature.
Quantum Tunneling: A particle can pass through a potential barrier even if its energy is less than the barrier height — there is a nonzero probability of being found on the other side.