J.J.+Thomson

J.J. Thomson [] [] [] //** Explain the importance of Thomson’s experimentation with the Cathode Ray Tube. **// His experiment helped him conclude that the rays in the tube are really small parts of atoms floating around called "corpuscles" but in reality, he found what is today called "electrons". He figured out that they make up all the matter in atoms. Most people thought that the atom was the smallest item and couldn't be broken apart, but this experiment proved that the atom could be broken up into smaller pieces. **//Summarize his model of the atom.//** Thomson's version of the atom is called the Plum Pudding model. The atom is compos ed of electrons. The atom is surrounded by a soup of positive charge to balance the electrons' negative charges. It explains how the atom keeps it shape and uses the charges of electrons to keep it together. //** 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? **//

//**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's theory was: All matter is composed of atom Atoms cannot be made or destroyed All atoms of the same element are identical Different elements have different types of atoms Chemical reactions occur when atoms are rearranged Compounds are formed from atoms of the constituent elements.

Thompson's theory basically added on to Dalton's theory. They both figured out that atoms are made of smaller item, and that all matter is made up of electrons. Thomson proved that even atoms are created of elements. Dalton was wrong when he said that the atom was just one thing not made up of anything.