 How does Teena find out about radioactivity?
You couldn’t have a father who was head of the atomic-science department at Oceanview College without picking up a little knowledge along the way. When carefully controlled, the radiation stored up in such isotopes was used in many beneficial ways. 20 Eddie went inside and followed Teena to the kitchen. They had been ever since Eddie’s family had moved to Oceanview and his father had become head of the college’s atomic-science department. Teena’s father was chief engineer for the Acme Aviation Company, one of the coast town’s largest manufacturing concerns. 22 “Oh, yes, it’s fun, Mother,” Teena replied, wrapping wax paper around a sandwich. There were slight traces of radioactivity in almost all earth or rocks.
 Eddie teaches Teena and her mother about about radioactivity after the news gets out about Mr. Taylor’s isotope being stolen.
 Eddie teaches her about radioactivity during their hike to Cedar Point.  Eddie teaches her about radioactivity while he helps her finish doing the dishes.  Eddie teaches her about radioactivity when he is explaining the dream he had about Cedar Point.  Eddie teaches Teena and her mother about about radioactivity after the news gets out about Mr. Taylor’s isotope being stolen.