ALEX Classroom Resource


Radioactive Decay of Carbon-14

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Radioactive Decay of Carbon-14


Content Source:

Type: Audio/Video


In this video excerpt from NOVA: "Hunting the Elements," New York Times technology columnist David Pogue explores how isotopes of carbon can be used to determine the age of once-living matter. Learn how variations in atomic structure form isotopes of an element and how the three natural isotopes of carbon differ from each other. Meet paleoclimatologist Scott Stine, who uses radiocarbon dating to study changes in climate. Find out what it means for an isotope to be radioactive and how the half-life of carbon-14 allows scientists to date organic materials.

Content Standard(s):
SC2015 (2015)
Grade: 9-12
Physical Science
6 ) Develop models to illustrate the concept of half-life for radioactive decay.

a. Research and communicate information about types of naturally occurring radiation and their properties.

b. Develop arguments for and against nuclear power generation compared to other types of power generation.

NAEP Framework
NAEP Statement::
P12.11: Fission and fusion are reactions involving changes in the nuclei of atoms. Fission is the splitting of a large nucleus into smaller nuclei and particles. Fusion involves joining two relatively light nuclei at extremely high temperature and pressure. Fusion is the process responsible for the energy of the Sun and other stars.

NAEP Statement::
P12.15: Nuclear reactions (fission and fusion) convert very small amounts of matter into appreciable amounts of energy.

Unpacked Content
Scientific And Engineering Practices:
Developing and Using Models; Engaging in Argument from Evidence; Obtaining, Evaluating, and Communicating Information
Crosscutting Concepts: Systems and System Models; Energy and Matter
Disciplinary Core Idea: Matter and Its Interactions
Evidence Of Student Attainment:
  • Research and analyze science texts for radioactivity.
  • Communicate information obtained from various sources about types of naturally occurring radiation and their properties.
  • Engage in argument from evidence obtained from various sources for and against nuclear power generation compared to other types of power generation.
  • Develop and use a model to illustrate the concept of half-life for radioactive decay.
Teacher Vocabulary:
  • Atom
  • Isotopes
  • Protons
  • Neutrons
  • Electrons
  • Radioactivity
  • Half-life
  • Radioactive decay
  • Alpha particles
  • Beta particles
  • Positrons
  • Gamma
  • Fission
  • Fusion
  • Kinetic energy
  • Electromagnetic radiation
  • Emission
  • Nuclear power
  • Hydroelectric power
  • Solar power
  • Wind power
  • Penetrability
  • Fossil fuel combustion
  • Decay series
Students know:
  • The atom is made of protons, neutrons, electrons.
  • The types of radioactive decay include alpha, beta, and gamma.
Students are able to:
  • Exemplify the radioactive decay of unstable nuclei using the concept of half-life.
  • Perform simple half-life calculations based on an isotope's half-life value, time of decay, and/or amount of substance.
  • Cite specific textual evidence to support analysis of science and technical texts attending to the precise details of explanations or descriptions.
  • Determine the central ideas or conclusions of a text; trace the explanation or depiction of a complex process, phenomenon, or concept; provide an accurate summary of the text distinct from prior knowledge or opinions.
  • Engage in argument from evidence.
  • Communicate information.
Students understand that:
  • Nuclear processes, including fusion, fission, and radioactive decays of unstable nuclei, involve release or absorption of energy.
  • Half-life can be used to date the age of organic objects.
AMSTI Resources:
ASIM Chemistry Module:
Analyzing Radiation; Half-Life Simulation
Tags: atom, carbon, electron, isotopes, proton, radioactive decay
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Author: Stephanie Carver