Related Experiment Video
Updated: Jun 20, 2026
10:42
Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
J. J. Thomson goes to America
1School of Molecular and Microbial Biosciences, The University of Sydney, Sydney, NSW, Australia. kdownard@usyd.edu.au
Journal of the American Society for Mass Spectrometry
|September 8, 2009
Summary
J. J. Thomson, discoverer of the electron, made significant contributions to nuclear physics. This article details his North American travels and scientific observations in the early 1900s.
Area of Science:
- Nuclear Physics
- Atomic Physics
- Physical Chemistry
Background:
- Joseph John (J. J.) Thomson's foundational work in nuclear physics.
- Thomson's discovery of the electron and Nobel Prize for studying electricity conduction in gases.
- His tenure as Cavendish Professor and Director of the laboratory, mentoring notable scientists.
Discussion:
- Recounts J. J. Thomson's four visits to North America between 1896 and 1923.
- Details his activities and personal impressions of American and Canadian society.
- Explores his observations on atomic physics and chemistry in the late 19th and early 20th centuries.
Key Insights:
- Thomson's electron discovery revolutionized understanding of atomic structure.
- His laboratory fostered a generation of leading physicists.
- His North American visits provided insights into international scientific exchange.
Outlook:
- Understanding the impact of J. J. Thomson's travels on scientific discourse.
- Appreciating his influence on the development of atomic physics and chemistry.
- Recognizing his role in shaping modern physics through his research and mentorship.
Related Concept Videos
01:19Thomson's e/m Experiment
In a beam of charged particles created by a heated cathode, the particles move at different speeds. However, many applications need a beam with uniform particle speeds. An arrangement known as a velocity selector uses electric and magnetic fields to pick particles with a particular speed from the beam.
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...
01:23The Joule and Joule–Thomson Experiments
Consider an adiabatic system composed of two chambers, A and B, designed such that no heat flows into or out of the system. Initially, chamber A is filled with a gas at a fixed temperature T1, pressure p1, and volume V1, while chamber B is evacuated. The gas is then gradually forced through a rigid, porous barrier to chamber B, ultimately reaching temperature T2, pressure p2, and volume V2. A piston on the right side maintains a constant pressure (p2), which is lower than p1. The significant...
01:21Joule-Thomson Effect
The Joule-Thomson effect, also known as the Joule-Kelvin effect, describes the temperature change of a fluid when it is forced through a valve or porous plug while keeping it in a thermally insulated environment. This experiment is called a throttling process. This is an important effect widely used in refrigeration and the liquefaction of gases.
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
01:09Electron Behavior
Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
00:54Electron Behavior
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.Electrons Orbit the NucleusElectrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus...
02:45The Quantum-Mechanical Model of an Atom
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger...