Radioactive Decay Lesson Plan Objectives Today I will

Radioactive Decay Lesson Plan

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

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

Warm - Up 1. What are the symbols for alpha, beta, and gamma decay? 2. Write the alpha decay for Thorium-235 3. Write the gamma decay for Cesium-135

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.

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

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

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

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

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

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

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

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

Half-Life Practice Problems 1. The half-life of carbon-14 (14 C) is 5, 730 years. If a sample originally contained 3. 36 g of carbon-14, how much is present after 22, 920 years? 1. 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?

Task: Calculate your radiation exposure

Radioactive Energy Spread

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

Closure