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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Node

A point, surface or plane where a wave or wavefunction is zero, so the probability of finding the particle there is zero. The sign of ψ\psi changes across a node, and more nodes means a shorter wavelength and a higher energy.

Particle-in-a-box wavefunction ψWavefunction between walls at x = 0 and x = L with 4 lobes and 3 interior nodes (marked with circles).V = ∞V = ∞0Lxψ

ψ4\psi_4 in a box has 3 interior nodes; the walls do not count.

Example

A particle-in-a-box ψn\psi_n has n−1n - 1 nodes, so ψ3\psi_3 has 2, at L/3L/3 and 2L/32L/3. An atomic orbital has n−1n - 1 nodes in total: 3p has 2 (one radial, one angular).

See alsoRadial nodeAngular nodeWavefunctionStanding wave