With the radon measurement activities at Stockholm House of Science, nuclear and experimental physics is introduced in a way that attracts the attention and interest of the students. These projects give the students the opportunity to use mobile detectors, either in their school, in the House of Science or in their homes. During 2006, 34 radon experiments were organized for school classes or groups of students. There were 21 shorter activities, ten one-day projects and three projects lasting for one or more weeks. Because of the popularity of the radon project, it will be extended with the introduction of more mobile detectors. (Contains 8 figures.)