JJ Thomson
Birth and death years and location
Birth: December 18th, 1856, Cheetham hill near Manchester, United Kingdom Death: August 30th, 1940, Cambridge, United Kingdom
During what years did the scientist do most of his/her work?
From age 14: went to Trinity college, continued to work until 1940: the year of his demise
What did he conclude about the atom?
He began studying cathode rays in 1894. Cathode rays are glowing beams of light that follow an electrical discharge in a high-vacuum tube. Thomson determined that all matter is made up of tiny particles that are much smaller than atoms. He called these particles 'corpuscles,' but now are called electrons. This discovery opposed the theory that the atom was the smallest fundamental unit. J.J. Thomson was "wrong" because he assumed that the electrons and the positive charge of an atom were all one uniform blob of matter.
How did they collect data? (Qualitative/Quantitative)
He calculated angles of deflection and ratios of electric charge by observing (Quantitative).
If they did a true experiment, explain the methods/set up.
He passed rays through a vacuum to measure the angle they were deflected at, and to calculate a ratio of electrical charge.
What tools did the scientist use to collect data?
He used a high-vacuum cathode-ray tube- a vacuum tube that creates a focused beam of electrons that can be deflected by electric fields, magnetic fields, or both.
How did his/her background lead to the research and discoveries?
His father pushed him to become an engineer and he went to college at a very young age, so he had a rich background in physics and scientific studies. He quickly earned a membership in the prestigious royal society. He was also appointed Rayleigh's successor as the Cavendish professor of physics at age 28. This all led to his discovery of electrons.
If they made a model, show their model and explain what it shows.
If they made a model, show their model and explain what it shows.
How does this discovery affect chemistry today?
JJ Thomson helped with the discovery of electrons. His main contribution to chemistry was showing the clear identification of electrons.
Did they work on any other projects/concepts?
Thomas's third experiment: He wanted to find the basic properties of particles. From this data he could calculate the ratio of the mass of a particle to its electric charge (m/e). He collected data using a variety of tubes and using different gases.
How did his research lead to this contributions?
his research in cathode ray led to the discovery of electrons. He discovered the electron, cathode ray experiment, and plum pudding model which was later disapproved. "The Plum Pudding Model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom. He therefore proposed that atoms have structure similar to a plum pudding, with tiny, negatively charged electrons embedded in a positively charged substrate. This was later shown to be incorrect."https://www.learner.org/courses/physics/glossary/definition.html?invariant=plum_pudding The plum pudding model suggested that an atom is a sphere with positive with negatively charged electrons scattered around. Relate to cookie. Chocolate chips are negatively charged electrons which are positioned in the positively charged area which is the cookie.
