Respuesta :
I think you forgot to add the options but based on my research the correct answer is "cathode-ray tube." This is the device made by J. J. Thomson to process and detect electrons is the: magnetron Geiger counter cathode-ray tube vacuum tube. Thank you for posting your question. I hope that this answer helped you. Let me know if you need more help.
Answer:
cathode-ray tube
Explanation:
J. J. Thomson performed the cathode ray tube experiment in which he showed that an atom is made up subatomic particles that are negatively charged. By shooting electricity through the cathode ray tube Thomson showed that the cathode rays are negatively charged. The rays were deflected by both electric and magnetic field. After his cathode ray experiment Thomson proposed the plum pudding atomic model.