This learning aid addresses the concept of half-life. It includes class notes for students, annotated class notes for teachers and students as well as a worksheet for students to practice calculations relating to the half-life of radioactive isotopes. An answer key is included with detail work on most problems. The student notes also include a link to my nuclear chemistry and half-life calculations lesson. This is an all-in-one lesson designed to facilitate your teaching of isotopes and half-lif