Skip to content

Discovery of Atomic Nucleus and Rutherford model of the atom

01/01/190901/01/1911
.

Rutherford atomic model, also called nuclear atom or planetary model of the atom, description of the structure of atoms proposed (1911) by the New Zealand-born physicist Ernest Rutherford. Rutherford directed the famous Geiger–Marsden experiment in 1909 which suggested, upon Rutherford's 1911 analysis, that J. J. Thomson's plum pudding model of the atom was incorrect. Rutherford's new model for the atom, based on the experimental results, contained the new features of a relatively high central charge concentrated into a very small volume in comparison to the rest of the atom and with this central volume also containing the bulk of the atomic mass of the atom. This region would be known as the "nucleus" of the atom.

Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure. If Thomson was correct, the beam would go straight through the gold foil. Most of the beams went through the foil, but a few were deflected by the foil and hit a spot on a screen placed off to one side. One in 20,000 alpha particles had been deflected 45º or more. Rutherford asked why so many alpha particles passed through the gold foil while a few were deflected so greatly. The only explanation is that there would be a mass agglomerate that would have a positive charge and repel the alpha particle, causing the scattering.

The model described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons, circulate at some distance, much like planets revolving around the Sun.


Geiger–Marsden experiment

A replica of one of Geiger and Marsden's apparatus
Gold foil experiment

Rutherford's article on the scattering of alpha particles

Rutherford's Model of an Atom
The Discovery of the Atomic Nucleus

REFERENCES

TIPLER, P. A. e LLEWELLYN, R. A. Modern Physics. 6ª ed. Freeman and Company, 2012. p. 156-162.

Encyclopædia Britannica. Available in: https://www.britannica.com/science/Rutherford-atomic-model. Access in: 24/08/2018.

Encyclopædia Britannica. Available in: https://www.britannica.com/science/atom/Discovery-of-radioactivity#ref496652. Access in: 03/09/2018.

0 comments

Comment
No comments avaliable.

Author

Info

Published in 24/08/2018

Updated in 19/02/2021

All events in the topic Quantum Mechanics:


01/01/1900Planck's quantum hypothesisPlanck's quantum hypothesis
01/03/1904Thomson Atomic ModelThomson Atomic Model
01/01/1918Planck receives Nobel PrizePlanck receives Nobel Prize
01/01/1906J. J. Thomson receives Nobel PrizeJ. J. Thomson receives Nobel Prize
01/01/1913Bohr's atomic modelBohr's atomic model
05/01/1923Compton EffectCompton Effect
01/01/1924de Broglie hypothesisde Broglie hypothesis
01/01/1929de Broglie receives the Nobel Prize
01/01/192512/01/1927Heisenberg's quantum mechanicsHeisenberg's quantum mechanics
01/01/1932Heisenberg receives Nobel PrizeHeisenberg receives Nobel Prize
01/01/1933 • 01:00:00Schrödinger and Dirac share the Nobel PrizeSchrödinger and Dirac share the Nobel Prize
01/01/1926Schrödinger's Quantum MechanicsSchrödinger's Quantum Mechanics
01/06/1927Wave–particle dualityWave–particle duality
01/01/1922Spin and the Stern-Gerlach experimentSpin and the Stern-Gerlach experiment
01/01/1943Otto Stern receives the Nobel PrizeOtto Stern receives the Nobel Prize
24/03/1928Relativistic quantum mechanicsRelativistic quantum mechanics
01/01/1930Applications of quantum mechanicsApplications of quantum mechanics
01/12/1930Prediction of NeutrinoPrediction of Neutrino
01/01/1956Experimental discovery of NeutrinoExperimental discovery of Neutrino
01/10/1945Wolfgang Pauli receives Nobel PrizeWolfgang Pauli receives Nobel Prize