1. JJ Thomson Background Information -Born December 18, 1856 -Cheetham Hill, Manchester, England -Studied at Owen's College, Trinity College, and Cambridge University -Died in 1940

2. Experimental Design I -Cathode rays are tubes with an anode at one end and a cathode at the other end. When a voltage is applied, electricity travels from the cathode to the anode

3. Experimental Design II -Thomson speculated that cathode rays were made of particles which he called “corpuscles” that came from within the atoms of the electroids. -Meaning they were divisible -He imagined these corpuscles swarming in a sea of positive charge: Chocolate Chip Cookie Model

4. Structure -Electrons were small particles of negative energy -They floated in a cloud of positive energy with no definite pattern -He was the first to identify subatomic particles

5. Postulates -Electrons exist. -The Chocolate Chip Cookie Model -Electrons played a part in chemical bonding

6. Evidence to Support These Theories -Measured the effects of magnetic/electric fields, calculated the ratio. -No evidence for the composition of atoms of strictly electrons.

7. Works Cited www.aip.org Chemistry, Glencoe Science