 How does Teena find out about radioactivity?
YOUNG READERS Atom Mystery 11 CHAPTER ONE It was only a dream. Then, remembering the dream, he added, “Oh, Dad, is it all right if I use the Geiger counter today?” “You may use the Geiger counter any time you want, Eddie,” Mr. Taylor said, “as long as you take good care of it. It was out on Cedar Point. Suddenly the Geiger counter began clicking like everything.” But, from what I hear, there are plenty of rock formations. Still, one clue is as good as another when it comes to hunting uranium ore, I guess. He washed hurriedly, knowing that even if he missed a spot or two, he was fairly safe. During the summer months his freckles got so thick and dark that it would take a magnifying glass to detect any small smudges of dirt hiding among them. He plastered some water on his dark-red hair, pushed a comb through it, and shrugged as it snapped back almost to its original position. The tooth-straightening orthodontist had warned him about letting food gather around the metal clamps. It could start cavities. “Aw, Mom—” “Eddie, I asked you to do it three days ago. Get at it right away, and you’ll still have time to hunt your uranium. In fact, anything having to do with atomic science excited him. He knew something about isotopes—pronounced eye-suh-tope . 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. Eddie knew that a radioisotope was a material which had been “cooked” in an atomic reactor until it was “hot” with radioactivity. When carefully controlled, the radiation stored up in such isotopes was used in many beneficial ways. One reason for asking that particular question was to keep from prying deeper into the subject of the radioisotope. Much of his father’s work at Oceanview College was of a secret nature. His father usually volunteered any information he wanted known, so Eddie stuck to questions which could and would be answered. At the speed atomic science is moving today, we simply can’t afford to waste time. It took Eddie over an hour to sort out the newspapers and magazines in the garage, tie them in neat bundles, and place them out on the front curb for the Goodwill pickup. “Anything else, Mom?” he asked, returning to the house and getting the Geiger counter out of the closet.
 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.