Radiometric dating lesson
Age estimates can be cross-tested by using different isotope pairs.
Results from different techniques, often measured in rival labs, continually confirm each other.
These skeptics do not provide scientific evidence for their views.
Current understanding of the history of life is probably close to the truth because it is based on repeated and careful testing and consideration of data.
The universe is full of naturally occurring radioactive elements.
Radioactive atoms are inherently unstable; over time, radioactive "parent atoms" decay into stable "daughter atoms." When molten rock cools, forming what are called igneous rocks, radioactive atoms are trapped inside. By measuring the quantity of unstable atoms left in a rock and comparing it to the quantity of stable daughter atoms in the rock, scientists can estimate the amount of time that has passed since that rock formed.
Teach your students about absolute dating: Determining age of rocks and fossils, a classroom activity for grades 9-12.
The fossil record is fundamental to an understanding of evolution.
Fossils document the order of appearance of groups and they tell us about some of the amazing plants and animals that died out long ago.
Fossils are generally found in sedimentary rock not igneous rock.
Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years.