Recording-2025-02-18T14:27:52.293Z

Definition: A method used to determine the exact age of rocks or fossils through the decay of radioactive isotopes.
- Utilizes the known rates of decay from unstable isotopes to stable ones.
Key Concepts:
- Isotopes: Variants of elements that have the same number of protons but different numbers of neutrons.
- Radiometric Decay: The process by which a parent isotope transforms into a daughter isotope over a specific period of time.
- Half-Life: The time required for half of the parent atoms in a sample to decay into daughter isotopes, which is crucial in calculating the age of the sample.

Eons of Earth’s History: Understand the major eons that mark the Earth’s history, particularly focusing on transitions between them.
- The first eon before the Archean is known as Hadean.
- Hadean Eon: Covers the time period from Earth's formation to the beginning of the Archean eon, focusing on the earliest conditions and geological activity.

Chart on Exam: A chart representing the radiometric decay and isotope names will be provided.
- Memorization Required: Be prepared to recall the names and characteristics of the isotopes presented on the chart.
- This knowledge will be applicable in discussions of Earth’s history and geological time progression.