The purpose of this assessment probe is to elicit students’ ideas about neutral atoms. The probe is designed to reveal how students think about the relationship between fundamental particles inside the nucleus of an atom. It is best used with students in grades 9–12, and can be extended by asking students to explain what neutral atom means to them. 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.