Geologic Time Part 2 - Radiometric or Absolute Dating

These flashcards cover key vocabulary terms related to geologic time and radiometric dating methods discussed in the lecture.

Radiometric Dating

A method used to date materials by determining the relative proportions of specific radioactive isotopes.

Radioactive Decay

The process by which an unstable atomic nucleus loses energy by emitting radiation.

Alpha Particles

Subatomic particles emitted during radioactive decay with an atomic weight of 4 and a charge of +2.

Beta Particles

Electrons emitted when a neutron decays into a proton and an electron during radioactive decay.

Gamma Rays

High-frequency electromagnetic waves emitted during radioactive decay with no mass and no charge.

Half-Life

The time required for half of the radioactive parent isotopes to decay into stable daughter products.

Isotopes

Variants of a chemical element that contain the same number of protons but different numbers of neutrons.

Parent Element

The original radioactive isotope that undergoes decay.

Daughter Element

The stable product formed from the decay of a radioactive parent element.

Mass Spectrometer

An instrument used to measure the quantities and masses of atoms and isotopes.

Stable Isotopes

Isotopes that do not undergo radioactive decay.

Radioactive Isotopes

Isotopes that are unstable and decay over time, emitting radiation.

Geologic Time Scale

A system of chronological dating that relates geological strata to time, used to describe the timing and relationships of events in Earth's history.

Carbon-14 Dating

A method for radiometric dating that uses the ratio of carbon-14 to carbon-12 to determine the age of organic materials.

Uranium-238

A radioactive isotope used in radiometric dating with a half-life of about 4.5 billion years.

Potassium-40

A radioactive isotope used for dating rocks with a half-life of 1.25 billion years.

Cation

An ion with a positive charge, formed when an atom loses one or more electrons.

Anion

An ion with a negative charge, formed when an atom gains one or more electrons.

Decay Rate

The speed at which a radioactive isotope decays into a stable product.

Geologic Record

The history of Earth as preserved in the geological layers of rocks and fossils.

Radiogenic Age

The calculated age of a rock or mineral based on the concentration of radioactive isotopes and their decay products.