J.J. Thomson
His model of the atom
Covered in this lesson
• This lesson explains JJ Thomson's experiments that led to the discovery of the electron.
– The discovery of negatively charged electrons smaller than the atom using a cathode ray tube.
Cathode Ray Tube
• A cathode ray tube is a glass tube with most of the air taken out and metal on both ends.
• An electrical current is applied (electron beam)
(diagram wikipedia)
Discovery of the Particles, We Call Electrons
• J.J. Thomson found the beam was deflected by electric and magnetic fields.
• He determined the beam consisted of negatively charged particles smaller than atoms that we now call electrons.
• He found electrons in atoms of various metals and suggested they are found in all atoms.
J. J. Thomson’s Model
J.J. Thomson’s model of the atom consists of a sphere filled with a positively charged cloud containing negative particles (electrons) spread throughout the cloud.
(diagram wikipedia)