Radioactive Decay/Absolute Dating
A half life refers to what?
The amount of time it takes for a mass of isotope to decay by 50%.
How many periods are within the Mesozoic era?
3.
When did the Paleozoic era begin?
~ 543 MYA.
Mammals.
What is it called when you determine the number of years that have elapsed since an event occurred?
Absolute dating.
What was the dominant species during the Mesozoic era?
Reptiles (dino).
Invertebrates.
When did humans show up within the Cenozoic era?
The Neogene era (second part of the Cenozoic era).
Geologists use ________, based on the natural radioactive decay of certain elements as reliable clocks to date ancient events.
The radiometric dating method.
What is the last period in the Mesozoic era?
Cretaceous.
What famous "explosion" occurred within this era?
The cambrian explosion.
When did this era end?
It didn't (it's ongoing).
The isotope that forms as a product of radioactive decay is:
Daughter isotope.
What occurred at the end of the Mesozoic Era?
The mass extinction primarily caused by an asteroid.
How many ice ages were there?
2.
What caused the beginning of the Cenozoic Era?
The Cretaceous-Paleogene extinction.
What is relative dating?
Rocks and structures being placed into chronological order, establishing the age of one thing as older or younger than another.
How long ago was the Mesozoic era?
~186 MYA.
What are the six periods within the Paleozoic era?
Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian.
This epoch, also known as the ice age, was called what?
Pleistocene.