This assessment probe is to elicit students’ ideas about radiation and is designed to reveal whether students distinguish between something that had been exposed to radiation (irradiated) versus something that is radioactive. It is best used with students in grades 8–12 and should be followed up with opportunities for discussion, argumentation, and sense-making activities. If students are not clear what the word irradiation means, explain it as the process in which something is exposed to the very high-energy waves or rays given off by a radioactive material. The probe is provided in English and Spanish. A materials list, teacher notes, standards, assessment, and references are provided. This book selection also includes the Table of Contents, Preface, Acknowledgments, Dedication, About the Authors, Introduction, and Index.