Close Contents Introduction Podcast Beta Questions and Answers More Actions PDF Questions Make a copy Study Flashcards Play Quiz Podcast Beta Play an AI-generated podcast conversation about this lesson 0.7x 0.9x 1x 1.1x 1.3x 1.5x 1.7x 2x Questions and Answers Download PDF PDF Questions PDF Answers What did JJ Thompson discover? The electron (correct) The neutron The proton The nucleus