J. J. Thomson

Physics British 1856 – 1940 395 quotes

Discovered the electron and proposed the first model of the atom.

Most quoted

"As the cathode rays carry a charge of negative electricity, are deflected by an electrostatic force as if they were negatively electrified, and are acted on by a magnetic force in just the way in which this force would act on a negatively electrified body moving along the path of these rays, I can see no escape from the conclusion that they are charges of negative electricity carried by particles of matter."

— from Cathode Rays, 1897

"We have, in the cathode rays, matter in a new state, a state in which the subdivision of matter is carried very much further than in the ordinary gaseous state: a state in which all matter—that is, matter derived from different sources such as hydrogen, oxygen, etc.—is of one and the same kind; this matter being the substance from which all the chemical elements are built up."

— from Philosophical Magazine, 1897

"We have in the cathode rays matter in a new state, a state in which the subdivision of matter is carried very much further than in the ordinary gaseous state: a state in which all matter—that is, matter derived from different sources such as hydrogen, oxygen, etc.—is of one and the same kind; this matter being the substance from which all the chemical elements are built up."

— from Cathode Rays, 1897

All quotes by J. J. Thomson (395)

The velocity of the cathode rays is very much less than that of light.

Cathode Rays 1897

The ratio of the mass of the electron to its charge is very small compared with the corresponding ratio for the hydrogen ion in electrolysis.

Cathode Rays 1897

The mass of the electron is only about 1/1800 of that of the hydrogen atom.

Further Experiments on the Cathode Rays 1899

The whole atom is built up of positive and negative electricity.

On the Structure of the Atom 1904

The number of electrons in an atom is approximately proportional to its atomic weight.

On the Structure of the Atom 1904

The atom is an electrical structure.

Attributed remark

The discovery of the electron has bridged the gap between electricity and matter.

Attributed remark

The corpuscles are the vehicles by which electricity is carried through metals.

Conduction of Electricity Through Gases 1900

The rays from radioactive substances consist in part of electrons.

Conduction of Electricity Through Gases 1903

The positive rays are atoms or molecules which have lost one or more electrons.

Rays of Positive Electricity 1913

The study of positive rays may throw light on the structure of molecules.

Rays of Positive Electricity 1913

The method of positive rays is a new method of chemical analysis.

Rays of Positive Electricity 1913

In the discharge tube we have a means of breaking up molecules into their constituent atoms.

Attributed remark

The laws of electrolysis find a simple explanation on the electron theory.

Conduction of Electricity Through Gases 1903

The conductivity of metals is due to free electrons.

Conduction of Electricity Through Gases 1900

The emission of electrons from hot bodies is a phenomenon of great importance.

Conduction of Electricity Through Gases 1903

The photoelectric effect is due to the ejection of electrons by light.

Attributed remark

The X-rays are produced when cathode rays strike against a solid obstacle.

Cathode Rays 1897

The ionization of gases by X-rays is due to the electrons set free by the rays.

Conduction of Electricity Through Gases 1903

The scattering of X-rays by matter may give information about the number of electrons in the atom.

Attributed remark