1911

Rutherford model

Rutherford publishes his central-charge scattering model of the atom

Rutherford's famous nucleus paper never uses the word nucleus — and it says outright that the evidence could not tell whether the central charge was positive or negative.

May 1911, in the Philosophical Magazine

The May 1911 issue of Philosophical Magazine published Ernest Rutherford's “The Scattering of α and β Particles by Matter and the Structure of the Atom,” at volume 21, pages 669–688. There was no single dated discovery day: a brief account went to the Manchester Literary and Philosophical Society in February, and the manuscript is dated April.

Rutherford showed mathematically that rare, large-angle deflections could result from a single encounter with an intense electric charge concentrated at an atom's center, rather than from an accumulation of many small deflections.

About one alpha particle in eight thousand

The measurements were Geiger and Marsden's, from a program of scattering experiments on gold and other metals rather than one famous afternoon with a gold foil. Rutherford cited backscattering of about 1 in 8,000 alpha particles incident on a thick platinum plate.

Comparing his theory with those results, he concluded that the simplest explanation was a central charge confined to a very small volume — for gold, about 100 elementary charges. That displaced J. J. Thomson's diffuse-positive-charge account of large-angle scattering.

What the paper stopped short of

It calls the object a central charge throughout and never uses the word nucleus. Rutherford assumed a positive sign for convenience in the calculation, but stated that the scattering evidence did not determine the sign.

Nor did it place electrons in specified orbits; historians of physics describe that textbook “Rutherford model” as a later simplification. The tissue-paper-and-artillery-shell comparison was Rutherford's later recollection, not text from the 1911 paper.

Sources

Researched 23 Aug 2026 5 sources 2 audit passes Date corrected

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date corrected. The research places this at 1911-05.

What the sources leave uncertain

There was no single dated “discovery day.” The paper says a brief account was communicated to the Manchester Literary and Philosophical Society in February, the manuscript is dated April, and the full article appeared in May 1911.
Calling the 1911 object a positively charged “nucleus” is retrospective. Rutherford wrote “central charge,” explicitly said the scattering evidence did not determine whether its sign was positive or negative, and did not use the word “nucleus” in this paper.