7th; Absolute Dating Flashcards
Radioactive Isotopes
How scientists determine the absolute ages of rocks
Geologic Column
An ordered arrangement of rock layers that is based on the relative ages of the rocks (from samples taken from different locations), with the oldest rocks at the bottom and the youngest ones at the top.
Absolute Dating
Determining the age of an event or object in years
Isotopes
Atoms of the same element that have a different number of neutrons
Radioactive Decay
The breakdown of a radioactive isotope into a stable isotope of the same element or of another element
Parent Isotope
A radioactive isotope
Daughter Isotope
The stable isotope
Half-life
The average time needed for half of a sample of a radioactive isotope to undergo radioactive decay to form stable daughter isotopes.
What is half-life measured in?
units of time
Radiometric Dating
finding the absolute age of a sample by determining the relative percentages of a radioactive parent isotope and a stable daughter isotopes.
What are the best rocks for radiometric dating?
Igneous rocks
Why are igneous rocks best for radiometric dating?
When they form, minerals often contain only a parent isotope and none of the daughter isotopes. It makes the percentages easier to interpret and makes dating more accurate.
Can radiometric dating techniques be used to date sedimentary rock?
No
Radiocarbon Dating
A type of radiometric dating used to date organic remains of living organisms such as wood, bones, and shells.
Radioactive isotope found in all living things.
Carbon-14
