Time Periods
This is the first time period in Earth's history.
What is Precambrian?
Earth and the rest of our solar system formed from a cloud of gasses that were drawn together by
Gravity
This is why oxygen was absent from the Earth's early atmosphere:
What is photosynthesizing organisms, such as plants, had not yet appeared?
This is what scientists believe the Earth looked like 4.5 billion years ago:
What is a molten rock core with no solid land or oceans?
How long is one half life?
25 years
In this time period, mammals became the dominant land animals.
What is the Cenozoic Era?
Name of theory that started our universe with an explosion
Big Bang
key organelles inside complex cells were once independent prokaryotic microbes,
simple cells working together to make a complex cell
What is the endosymbiont theory?
Astronomical forces have also shaped climate on Earth.
Orbit Tilt Wobble
How many half lifes till only 25% of Strontium 90 is left?
2 half lifes
This time period means ancient life, and included many invertebrates, fish, and amphibians.
What is the Paleozoic Era?
Earths Structure
The _______ is made of extremely hot metal. Inner Section of Earth
Core
A one-million-year-old layer of sandstone lying on top of a 1.5 million-year-old layer of granite is an example of this law.
What is the Law of Superposition?
dating methods estimate whether an object is younger or older than other things
Relative Dating
Absolute Dating is measuring what?
Radioactive Atoms in rock/fossils
Dinosaurs were around in this time period.
What is the Mesozoic era?
How did Earth get Water?
2 Theorys
This is the model that expresses the major geological and biological events during Earth's history.
What is the Geologic Time Scale?
Stanley Miller and Harold Urey simulated early atmospheric conditions to test this idea on the origin of life.
What did they produce in their experiment?
amino acids
at 100 years how many half lifes have passed?
4
What is the Mesozoic Era?
Describe Earths Early Atmosphere
Toxic
Any geological feature—such as a fault, fold, or igneous intrusion—that cuts across or disrupts existing rock layers is younger than the rocks it disrupts.
Principle of Cross Cutting Concepts
dating gives a specific numerical age or date range
Absolute Dating
Daily Doube
Rock papers Scissors tournament