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Radioactive Review

Main Core Tie

Science - Chemistry
Standard 2 Objective 2

Time Frame

1 class periods of 30 minutes each

Group Size



Utah LessonPlans


This lesson consists of half-life problems for the students to work out.



Background for Teachers

Time Needed:
This can take up about 20 minutes in class and for those that don't finish, it can be homework.

Prior Knowledge:
These half-life problems can be given the day after teaching the students about how to calculate the half life of different elements

Instructional Procedures


  1. This is an example of a table students can use for every half- life problem. Here is an example from #4 on the Review:
  2. Give them the review to practice the half-life radioactive problems.

Assessment Plan

Scoring Guide:
Participation points can be awarded or make each answer worth 2 points. Here are the answers for the review:

  1. Ideally you should get as far from all the rocks as possible. If you must hold one and put one in your pocket, hold the alpha emitter because the skin on your hand will shield you. Put the beta emitter in your pocket because its rays might be stopped by the combined thickness of clothing and skin. Throw away the gamma emitter because its rays would penetrate deep into your body from either of these places.
  2. a)1/4, 1/8
    b)The elements transmute into another, and will keep transmute until they become a more stable element.
  3. 5.730 + 5,730 = 11,460 years
  4. As from the example table above, it would be 120 years.


Lesson Design by Jordan School District Teachers and Staff.

Created: 12/11/2014
Updated: 02/05/2018