1. Radioactive Decay Lesson Plan

2. Common Core Connection
Objectives: Today I will be able to: Identify the benefits and risks associated with the practical uses of alpha, beta and gamma emissions. Write balanced alpha and beta decay equations.
Informal assessment – monitoring student questions and interactions as they complete the decay equation practice
Formal assessment – analyzing student responses to the warm up, closure and alpha/beta decay practice problems
Common Core Connection
Build Strong Content Knowledge
Use technology and digital media strategically and capably
Reason abstractly and quantitatively
Look for and make use of structure
Make sense of problem and persevere in solving them

3. Lesson Sequence Evaluate: Warm Up (5-7 min)
Explain: Writing Decay Equations (15 min)
Elaborate: Decay Equation Practice (20 min)
Informal assessment of student questions and responses
Formal assessment of student answers
Evaluate: Closure (5-7 min)
Formal assessment of meeting the objectives

4. Warm - Up What are the symbols for alpha, beta, and gamma decay?
Write the alpha decay for Thorium-235
Write the gamma decay for Cesium-135

5. Objectives Today I will be able to:
Identify the benefits and risks associated with the practical uses of alpha, beta and gamma emissions.
Write balanced alpha and beta decay equations.

6. Homework Study for your Unit 3 Exam on Thursday, October 14
Topics:
Atomic Structure
History of the Atom
Radioactivity
Complete the alpha and beta decay practice problems worksheet

7. Agenda Warm Up Writing Decay Equations Decay Equation Practice
Calculating your own radiation exposure
Closure

8. We can represent the energy emitted during radioactive decay using a decay equation

9. What are the pieces of a radioactive decay equation?
Radioactive Particle Symbol
New Decay Product
Unstable Isotope

10. Alpha Decay Equation Example
The Calvert Cliff’s nuclear power plant uses Uranium – 235. Write the alpha decay equation

11. Beta Decay Equation Example
The radioisotope yttrium-90 is used in cancer treatments. Write the beta decay equation.

12. Gamma Radiation Example
Gamma radiation is emitted from Uranium 235 at the nuclear power plant. Write an equation representing the gamma energy emitted.

13. What is radioactivity half-life?
Half – life : the time it takes for half of the atoms in a given mass to disintegrate (release radiation) and become more stable
Length of time varies
½ second to a billion years

14. Half-Life Practice Problems
The half-life of carbon-14 (14C) is 5,730 years. If a sample originally contained 3.36 g of carbon-14, how much is present after 22,920 years?
Gold-191 has a half-life of 12.4 hours. After one day and 13.2 hours, 10.6 g of gold-191 remains in a sample. How much gold-191 was originally present in the sample?

15. Task: Calculate your radiation exposure

17. Radioactive Energy Spread
Haz-map.com

18. What does your radiation exposure value mean?
No evidence of cancer occurring <10,000 mrem exposure
Body has time to repair cells when exposed to low concentrations of radiation
Correlation has been found with cancer and radiation exposure >50,000 mrem

19. Closure
Students will be re-polled on “Poll Everywhere” on the previous questions.
True or False. The negative risks of using nuclear energy outweigh the positive impacts.
True or False. Americans get most of their yearly radiation dose from nuclear power plants.