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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Probability density

The square of the wavefunction, ψ2\psi^2: the probability per unit volume (or length) of finding the particle at a point. Where ψ2\psi^2 is large the particle is likely to be found; at a node it is never found.

Particle-in-a-box probability density ψ²Probability density between walls at x = 0 and x = L with 2 lobes and 1 interior node (marked with circles).V = ∞V = ∞0Lxψ²

ψ22\psi_2^2: peaks at L/4L/4 and 3L/43L/4, zero at the centre.

Example

In the n=1n = 1 box state the particle is most likely at the centre, L/2L/2; in n=2n = 2 it is never found exactly there. An orbital drawing shows the region where ψ2\psi^2 is large.

See alsoWavefunctionNodeAtomic orbital