RadTown Radiation Exposure Activity 3: Penetrating Powers of Ionizing Radiation

Ionizing radiation is divided into four different types: alpha, beta, gamma, and x-ray radiation. Each type of radiation can be blocked, or shielded, by different materials. This activity uses common classroom items to help illustrate how different types of radiation can interact with our bodies. This activity is intended for middle and high school students.

• Objectives
• Next Generation Science Standards
• Materials and Resources
• Time
• Vocabulary
• Directions
• Common Core State Standards
• Printable Worksheets and Classroom Aids

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Objectives

Students will:

• Predict whether each type of ionizing radiation has the ability to penetrate, or pass through, our skin and body.
• Demonstrate the penetrating powers of ionizing radiation.
• Consider how we are exposed to radiation and how we can limit our exposure.
• Differentiate between radiation exposure and radiation contamination.

Next Generation Science Standards

The concepts in this activity can be used to support the following science standard:

• PS4. Waves and Electromagnetic Radiation

Materials and Resources

Each italicized document title can be found at the bottom of this page, and is available for printing and distribution.

• Radiation Exposure: Teacher Background Information
• Vocabulary Materials
• Penetrating Powers of Ionizing Radiation Worksheet demonstration materials:
  • Cardboard box (for a class demonstration or one box per group) with several holes in one side or a side covered with plastic mesh (from a hobby or hardware store); the holes/mesh size should be relative to the “beta particle” representations.
  • Lightweight objects to represent beta particles (e.g., a ping pong ball or small beads if using mesh). Some, but not all, of the objects should be able to fit through the cardboard or mesh holes. Mark objects with a negative symbol (–) to represent the negative charge of a beta particle if possible.
  • Larger beads or objects (e.g., a baseball or larger beads) to represent alpha particles. The objects should be heavier than the “beta particles” and not fit through the cardboard or mesh holes. Mark objects with a positive symbol (+) to represent the positive charge of an alpha particle if possible.
  • Flashlight to represent x-rays and gamma rays.
• Penetrating Powers of Ionizing Radiation Worksheet (one per student, pair or group) and Penetrating Powers of Ionizing Radiation Teacher Answer Key
• Penetrating Powers of Ionizing Radiation Image

Time

45-60 minutes, not including optional activities or extensions.

Vocabulary

• Alpha particles
• Beta particles
• Direct exposure
• Exposure pathways
• Gamma rays
• Ingestion
• Inhalation
• Ionizing radiation
• Radiation
• Radiation exposure
• Radiation protection
• Radioactive contamination
• X-rays

Directions

1. Start with a vocabulary activity if students are not familiar with radiation and the terms used in this activity, or provide students with the terms and definitions.
    
2. Distribute the Penetrating Powers of Ionizing Radiation Worksheet to students. Direct students to read and complete the first question.
    
3. Discuss students' predictions and their responses to the first question on the worksheet.
    
4. Explain that the students are going to help you demonstrate the penetrating powers of radiation, or the ability of radiation to pass through our skin and body.
    
5. Show students the alpha particle, beta particle, x-ray and gamma ray representations (see Materials and Resources for appropriate objects).
    
6. Ask for several student volunteers if conducting a class demonstration, or provide direction to students if having them conduct the demonstration in groups.
   • Explain that the cardboard box or mesh represents our skin.
   • Have at least two students try to toss the alpha particles (larger object like baseball or large beads) through the cardboard holes or pour them over the mesh. If tossing the alpha particles, direct at least one student to toss the alpha particle lightly so that it falls short of the cardboard box.
   • Ask students to think about what they saw and hypothesize why this occurred and how this relates to exposure to alpha particles. Alpha particles are heavy and may lack the energy to reach you and penetrate the outer dead layer of skin.
   • Have several students try to toss beta particles (smaller object like ping pong ball or small beads) through the cardboard holes or pour beta particles through the mesh. Some should make it through and some not. Ask students to hypothesize what occurred and how this relates to exposure to beta particles. The speed of individual beta particles depends on how much energy they have, and varies over a wide range. Some beta particles may have enough energy to penetrate our skin while others may not. NOTE: Alpha and beta particles may not have enough energy to penetrate skin or clothing, but if inhaled or ingested, alpha and beta particles can transfer large amounts of energy to surrounding tissue and damage cells. Radiation exposure can serve as a benefit; for example, in controlled situations when it is used to diagnose and treat diseases. In uncontrolled situations, like high radon levels in a home, radiation can pose health risks and concerns.
   • Ask a student to (or you) shine the x-ray and gamma ray representation through the cardboard or mesh. Be sure to turn the box so it’s facing the students and they can see the light shining through the holes/mesh or open the back side of the box so they can see the light shining through. Make sure the light is not directed toward another person. Ask students to hypothesize what occurred and how this relates to exposure to x-rays and gamma rays. X-rays and gamma rays are the most energetic. They can penetrate and pass through many kinds of materials, including our bodies.
      
7. Direct students to answer the remaining questions on the Penetrating Powers of Ionizing Radiation Worksheet.
    
8. Discuss students’ responses using the Penetrating Powers of Ionizing Radiation: Teacher Answer Key. You can also share the Penetrating Powers of Ionizing Radiation Image while reviewing students’ answers and the correct responses.
    
9. Conclude by having students share (verbally or in writing) at least one thing they have learned and how the activity changed their perceptions about radiation.
    
10. Optional activity or extension: Direct students to research radioactive elements and determine their penetrating power and how the penetrating power might serve as a risk or a benefit. A potential resource for students is EPA's Radionuclides webpage.

Printable Worksheets and Classroom Aids

• Penetrating Powers of Ionizing Radiation Worksheet (pdf) (129.1 KB)
• Penetrating Powers of Ionizing Radiation: Teacher Answer Key (pdf) (112.08 KB)
• Penetrating Powers of Ionizing Radiation Image (pdf) (201.65 KB)