Radiometric Dating

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Radiometric Dating Noun

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[ray-dee-oh-met-rik day-ting]

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Radiometric Dating

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A method used to determine the age of materials such as rocks or carbon, based on the decay of radioactive isotopes.

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Example: This graph shows that after each half-life, the amount of a radioactive substance decreases by 50%, a key principle for determining an object's age.

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Parent Isotope Noun

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[pair-ent ahy-suh-tohp]

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Parent Isotope

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A radioactive isotope that undergoes decay to form a more stable daughter isotope.

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Example: This diagram shows an unstable Parent Nucleus (the parent isotope) breaking down into a more stable Daughter Nucleus and an alpha particle.

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Daughter Isotope Noun

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[daw-ter ahy-suh-tohp]

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Daughter Isotope

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The isotope that is the product of radioactive decay of a parent isotope.

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Example: This diagram shows an unstable parent nucleus decaying into a new, more stable daughter nucleus by releasing a particle, a key process in radiometric dating.

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Half-life Noun

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[haf-lahyf]

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Half-life

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The time required for half of the radioactive atoms in a sample to decay.

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Example: This graph shows that after each half-life period, the amount of a radioactive substance like carbon-14 decreases by exactly half.

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Carbon-14 Dating Noun

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[kar-buhn fohr-teen day-ting]

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Carbon-14 Dating

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A specific method of radiometric dating used for organic materials up to about 60,000 years old.

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Example: This diagram shows that living organisms absorb Carbon-14. After death, the Carbon-14 decays at a known rate (its half-life), allowing scientists to determine a fossil's age.

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Cosmic Rays Noun

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[koz-mik reyz]

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Cosmic Rays

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High-energy radiation originating from outside the solar system, which can create C-14 in the atmosphere.

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Example: High-energy particles, called cosmic rays, are created by events like supernovas and travel through space at nearly the speed of light.

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Beta Decay Noun

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[bey-tuh di-key]

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Beta Decay

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A type of radioactive decay in which a beta particle is emitted from an atomic nucleus.

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Example: This diagram shows a Carbon-14 atom undergoing beta decay, where one of its neutrons turns into a proton, changing it into a Nitrogen-14 atom.

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Isotopic Fractionation Noun

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[ahy-suh-top-ik frak-shuh-ney-shuhn]

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Isotopic Fractionation

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A process that affects the relative abundance of isotopes, which can cause errors in radiometric dating.

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Example: During evaporation, lighter water molecules enter clouds more easily than heavier ones. This causes them to separate, with heavier water raining out sooner, which is isotopic fractionation.

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Calibration Curve Noun

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[kal-i-brey-shuhn kurv]

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Calibration Curve

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A graph used to convert an apparent radiometric age to a more accurate calendar age by accounting for past variations.

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Example: This graph shows how the amount of Carbon-14 decreases over time. Scientists use this known decay rate as a calibration curve to determine the age of ancient objects.

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Mass Spectrometer Noun

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[mas spek-trom-i-ter]

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Mass Spectrometer

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An instrument used to measure the masses and relative concentrations of atoms, often for determining isotope ratios in dating.

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Example: A mass spectrometer separates particles by mass. A sample is ionized, accelerated, and then bent by a magnet, which deflects lighter particles more.