40 Fun Facts About J. J. Thomson

Which dessert gave its popular name to J. J. Thomson's 1904 model of the atom, with electrons scattered like raisins?

Plum pudding was a nickname Thomson never used himself: a magazine reporter made the comparison in 1906, and it stuck to his picture of electrons set in a ball of positive charge.

J. J. Thomson proved the electron is a particle; his son George won a Nobel Prize for showing electrons act as what?

Waves are what George Paget Thomson revealed when he diffracted electrons through crystals, earning the 1937 physics Nobel, 31 years after his father's.

J. J. Thomson's ashes rest near the grave of Isaac Newton inside which famous London church?

Westminster Abbey took Thomson's ashes in 1940, placing the discoverer of the electron among the most honoured names in British science.

J. J. Thomson resisted the word 'electron' for years, preferring which name for the particles he had discovered?

Corpuscles was Thomson's word until about 1914. He disliked 'electron' because some physicists used it for a supposed positive particle too.

J. J. Thomson entered Owens College at just 14 in which English city, the place of his birth?

Manchester was home: Thomson was born in its Cheetham Hill suburb, and Owens College later grew into the city's university.

J. J. Thomson's parents planned for him to become an apprentice engineer building what, before his father died?

Locomotives were the family's plan, at the firm of Sharp, Stewart & Co, but his father's death in 1873 put the costly apprenticeship out of reach and he stayed in science.

A onetime assistant of Nobel-winning experimenter J. J. Thomson said it was necessary to discourage him from doing what?

Handling the apparatus was risky because Thomson was awkward with his fingers, his assistant H. F. Newall recalled, yet his ideas about how an experiment ought to go were invaluable.

Which metal, beaten into thin foil, was used in the 1909 experiment that helped sink J. J. Thomson's model of the atom?

Gold foil sent a few alpha particles flying backwards, which astonished the experimenters: Thomson's evenly spread atom should have let them all sail through.

Before J. J. Thomson found the electron in 1897, most people believed that atoms were what?

Indivisible was the accepted view, so Thomson's claim that even smaller pieces could be knocked out of atoms startled his fellow scientists.

J. J. Thomson showed that the particles streaming through his cathode ray tubes carry which kind of electric charge?

Negative charge reached Thomson's electrometer only when a magnet steered the rays onto it, proving that the charge and the rays could not be separated.

Which New Zealand-born student of J. J. Thomson went on to overturn his old teacher's model of the atom?

Ernest Rutherford arrived at Thomson's laboratory in 1895 on a research fellowship, and in 1919 he returned to take over his old professor's chair.

J. J. Thomson's 1904 atom fell out of favour when experiments showed that an atom's positive charge is packed into what?

A tiny nucleus at the centre holds all the positive charge, the reverse of Thomson's picture, in which that charge was spread evenly through the whole atom.

In 1906 J. J. Thomson showed that an atom of which element contains only a single electron?

Hydrogen has just one electron per atom, Thomson showed, ending a period in which rival theories had allowed all sorts of other numbers.

In 1905 J. J. Thomson discovered that which element, essential in the human diet, is naturally radioactive?

Potassium is faintly radioactive because a small share of it is the unstable isotope potassium-40, which is why radiation doses are sometimes jokingly counted in bananas.

J. J. Thomson's 1906 Nobel Prize in Physics honoured his studies of electricity passing through what?

Gases conducting electricity were the official reason for the prize: the Nobel citation never mentions the electron, the discovery Thomson is remembered for.

J. J. Thomson was only 28 when he was put in charge of which world-famous English physics laboratory?

The Cavendish was startled by the choice: one senior Cambridge figure grumbled that matters had come to a pretty pass when mere boys were made professors.

J. J. Thomson was made Master in 1918 of which Cambridge college, his home since his student days?

Trinity admitted Thomson on a scholarship in 1876, made him a Fellow a few years later, and kept him as a member for the rest of his life.

J. J. Thomson first announced the electron during an 1897 Friday evening discourse at which London venue?

Royal Institution audiences had gathered for Friday Evening Discourses since 1825, and Thomson used his on 30 April 1897 to unveil a particle far smaller than any atom.

As a child, long before physics, future Nobel laureate J. J. Thomson was mainly interested in which science?

Botany was the boy's first interest, and he had little exposure to physics or mathematics until he reached college as a teenager.

Which future quantum pioneer came to Cambridge in 1911 to work under J. J. Thomson but failed to impress him?

Niels Bohr did some research on cathode rays at Cambridge, got on better with the younger physicists, and soon left to build his own celebrated model of the atom.

In 1912 J. J. Thomson found atoms of which element in two weights, the first isotopes seen in a stable element?

Neon ions left two separate patches on Thomson's photographic plate, one for atoms of weight 20 and one for weight 22, after he bent the beam with magnetic and electric fields.

J. J. Thomson's 1912 sorting of atoms by weight was the first use of which laboratory technique?

Mass spectrometry was refined by others into a general method, and a unit used in it, the thomson, was later proposed in his honour.

Which assistant of J. J. Thomson won the 1922 Nobel Prize in Chemistry for finding isotopes in many more elements?

Francis Aston rebuilt his professor's positive-ray equipment into a far sharper instrument and used it to identify 212 naturally occurring isotopes.

J. J. Thomson took over Cambridge's top physics professorship in 1884 from which lord, the co-discoverer of argon?

Lord Rayleigh held the chair for five years, then resigned to carry on experimenting at his country home, Terling Place; his work on argon later won him a Nobel Prize of his own.

Which British monarch knighted Nobel laureate J. J. Thomson in 1908, two years after his prize?

Edward VII made him Sir J. J. in 1908, and four years later the next king admitted Thomson to the Order of Merit, an honour limited to 24 living members.

Rose Paget, who married J. J. Thomson in 1890, first got to know the physicist while doing what?

Attending his lectures put Rose Paget among the first generation of women allowed into advanced study at Cambridge, where she also ran experiments of her own on soap films.

J. J. Thomson's 1884 appointment to a top Cambridge physics chair caused surprise because he was known mainly as what?

A mathematician who had come second in Cambridge's gruelling final examination, Thomson was chosen over older rivals with far more experience of laboratory work.

J. J. Thomson bent cathode rays with an electric field where earlier experimenters had failed, by improving what?

The vacuum in earlier tubes was too poor: leftover air became electrically charged and screened the rays from the field, so the beam never seemed to move.

What do the initials stand for in the name of J. J. Thomson, the discoverer of the electron?

Joseph John was known to almost everyone simply as J.J.; his father shared his first name but had James as a second.

What kind of business did J. J. Thomson's father run, one founded by the physicist's great-grandfather?

A bookshop dealing in antiquarian volumes was the Thomson family trade, while his mother's relatives were in the local textile business.

The word 'electron' was coined in 1891, before J. J. Thomson's discovery, by which Irish physicist?

George Johnstone Stoney meant it as a name for the basic unit of electric charge, six years before anyone had found a particle to carry it.

J. J. Thomson's 1893 book on electricity was nicknamed the 'third volume' of which physicist's famous treatise?

James Clerk Maxwell had been the first holder of Thomson's own Cambridge professorship, and the sequel gathered up the results obtained since his famous Treatise.

J. J. Thomson's prize-winning early treatise worked out the mathematics of Lord Kelvin's theory that atoms were what?

Vortex rings, stable whirls in the ether then thought to fill all space, were a popular British picture of the atom, and Thomson's essay on them won Cambridge's Adams Prize.

J. J. Thomson crossed the Atlantic in 1896 to give four talks on his research at which American university?

Princeton heard him just before the breakthrough: on his return home, Thomson began the cathode ray study that revealed the electron.

J. J. Thomson overturned which German physicist's finding that cathode rays could not be deflected by an electric field?

Heinrich Hertz ran his test in 1883 and saw no deflection, in keeping with the German view that the rays were a disturbance in the ether, not a stream of particles.

Which student of J. J. Thomson won a Nobel Prize for inventing the cloud chamber, which makes particle tracks visible?

C. T. R. Wilson had studied cloud formation at the observatory on Ben Nevis before bringing the weather indoors at Thomson's laboratory.

The Thomson problem, posed by J. J. Thomson in 1904, asks how repelling electrons arrange themselves on what surface?

A sphere is the setting, and the puzzle is still open in general: it is related to one of the eighteen unsolved mathematics problems proposed by Steve Smale.

Thomson scattering, named for J. J. Thomson, explains the glow of which part of the Sun seen during total eclipses?

The corona's K component is sunlight scattered by free electrons, and solar observatories measure that glow to map the electron density around the Sun.

The glass discharge tubes J. J. Thomson used for his cathode ray work are named after which English chemist?

William Crookes, who also discovered the element thallium, invented the tube in the 1870s, two decades before Thomson used one to find the electron.

The cathode ray tubes J. J. Thomson experimented with later became the heart of which household device?

The television set grew out of the cathode ray tube invented by Ferdinand Braun in 1897, the very year Thomson announced the electron.