J.J.+Thomson

J.J. Thomson [] [] []

Explain the importance of Thomson’s experimentation with the Cathode Ray Tube.

Thomson experimented the Cathode Ray Tube which is a fluorescent glow from a glass tube with two wires at each end and pumping as much air out as you can. An electric charge passed through which created a fluorescent glow.

( picture: Cathode Ray Tube)

He discovered that the rays are streams of much smaller particles compared to atoms. He titled them ‘’corpuscles’’ or electrons. This disproved the fact that atoms were indivisable.

Summarize his model of the atom.

Thomson considered his model of the atom to be like raisin bread, his theory was called the “raisin bread model.” He said that the basic body of an atom is a spherical object containing N electrons confined in homogeneous jellylike but relatively massive positive charge distribution whose total charge cancels that of the N electrons. He developed the plum pudding model of the atom.

Atom Model of Thomson aka plum pudding

Thomson’s model changed our view of the atom. Compare and contrast his model to Dalton’s model. What new knowledge did we gain? What was wrong with Dalton’s model? Did any of Dalton’s ideas continue to be valid?

Dalton focused more on the nucleus while Thomson focused more on electrons. Dalton also said nothing is smaller than an atom, but Thomson said electrons are.