Electron Probability Cloud Simulator — Hydrogen 1s Position Measurements Interactive

Interactive 3D hydrogen 1s probability cloud: collect independent position measurements, move a radius gate, and compare measured counts with the exact radial probability.

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About the Electron Probability Cloud Simulator

Collect independent simulated position measurements from identically prepared hydrogen 1s states. The accumulation forms a spherical probability cloud; a movable radius gate compares measured counts with the exact radial probability.

What the simulator shows

• A hydrogen nucleus, independent position outcomes, a spherical probability gate, a central slice indicator and a radial probability profile. • Controls for the radius gate (Bohr radii a₀), measurements per second, a repeatable sampling seed and a thin central slice. • Four tabs: Observatory, Geometry & measurements, Experiments (with built-in model checks), and Learn & assess.

The mathematics

|ψ1s|² = exp(−2r/a₀)/(πa₀³); with x = r/a₀ the radial PDF is p(x) = 4x² exp(−2x). P(r < R) = 1 − exp(−2X)(1 + 2X + 2X²) with X = R/a₀. The mean radius is 1.5a₀ and the most probable radial distance is a₀. Samples use x = −½ ln(U1 U2 U3) with an isotropic direction.

Model boundaries

This is nonrelativistic hydrogen 1s only. It samples position statistics from repeated identically prepared atoms; it is not electron motion, a wavefunction-collapse time model or a many-electron atom. The sample cap is 4,000, the nuclear size is enlarged, and the slice affects displayed dots only.

Frequently asked questions

Are the dots one electron’s trajectory?

No. They are independent measurements on identically prepared states.

Is the radial probability largest at the nucleus?

No. Shell-volume weighting makes the 1s radial PDF peak at a₀, even though the probability density itself is highest at the nucleus.

What fraction of measurements fall within a given radius?

About 32.3% of measurements lie inside a₀ and about 93.8% lie inside 3a₀; sample estimates fluctuate around these exact values.

What are the limits of the probability cloud model?

It covers nonrelativistic hydrogen 1s only, with a 4,000-sample cap and an enlarged nucleus; it is not electron motion, a collapse-time model or a many-electron atom.

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