Featured below is a sample Chemistry lab involving nuclear decay. This resource is free for you to use for your classroom. In this example of a flipped lesson, students are expected to watch a 6 minute video and take notes for homework before coming to class where the information is ‘delivered’. A video guide could be given for students to help focus them as well as scaffold their note taking. In class they will work on applying that knowledge and skill in a small group setting where their peers and the instructor can intervene. This prevents students from practicing it incorrectly at home, and remember; practice makes permanent.

Classroom: High School Chemistry

Topic: Completing Nuclear Decay Equations

Objective: Students will be able to complete nuclear decay equations, solving for a missing element as well as missing radioactive particle(s).

Previously: Students on the previous day were introduced to radioactivity, decay particles, and the pertinent tables found on their regents chemistry reference tables (Table N and O).

Homework for the Night Before:


In Class Activity:

Warm Up:

Have the students complete the following Decay Equations:

  • 222Ra → ______ + 218Rn
  • 252Cf → 140Xe + 4 1n + _____
  • 198Au → _______ + ________

Give time for students to complete the do now and observe the data that is collected to inform what you need to focus on. While they are completing that, take attendance and hand back anything that needs to make it back.

    Go over the do now as a whole class, demonstrating how to successfully complete the problem(s) using their reference tables, answering any questions that they have and scaffold their acquisition of the skill described in the objective.




Students can be split into groups, put into stations, or work individually. It is up to the teacher to organize the lesson to fit the needs of the class. Each member should be required to contribute to the work in the activity, meaning that three different handwritings should be on the assignment sheet. Students should also be encourage to check each others' work.



In your groups and using your chemistry reference tables, complete the following table, making sure that each member contributes. When finished, discuss as a group the solution to the Thinking Question outlined below: 

Decay Mode
Decay Equation


Thinking Question: Iodine is an element that is found in high concentrations in the thyroid, an organ that helps regulate a person’s metabolism. Hyperthyroidism is a condition where the thyroid gland has overactive cells which increases the metabolism of an individual, resulting in a wide range of symptoms including restlessness, weight loss, increased appetite and rapid heart rate. Speculate on how 131I may be used in these situations.


While the students are working on these problems in their small groups, the teacher should be circulating and checking them as they go. The teacher should stop at each group and check off the problems as they complete them for accuracy and give intervention as needed by asking guiding questions or simply pointing out which problems deserve a second look. The students are also carrying out intervention with their fellow classmates because each student has a vested interest in how the group does gradewise. Afterwards, the teacher will go over the ‘Thinking Question’ and have that as a segue into applications of some of the radioisotopes in the worksheet while focusing on the decay equations and what it is that makes them applicable in that sense.



To close out the lesson, have students complete one additional decay equation independently and submit it at the end of the class. This can be done on paper or digitally. Students should also do a self-evaluation that includes summarizing what they learned in class, how confident they feel with the material, a question they didn’t get to ask and what the homework is for the night, which not only helps students solidify the learned material, and also gives the teacher feedback about the lesson and class progression. Below is an example of a generic form students could fill out using Google Forms:

Note: Under this Google Form system, students' school email accounts were auto-captured, giving the teacher the names of the students.