What Time is It?
Pieces of the Past
How old are you?
The Changing Earth
Anything Goes!
100
Eon
What is the largest unit of time for Earth's history?
100
fossils
What is a trace piece of evidence from the past?
100
relative age
What is a general comparison of how old something is to other items?
100
Pangaea
What is the name of the supercontinent separated during the Mesozoic Era?
100
geologic time scale
What is the organized chart of Earth's history?
200
Carboniferous
What is the time period with the largest plants and coal production?
200
minerals
What is replaces the material in an organism to make it a fossil?
200
index fossils
What fossils are used to determine age of surrounding rock?
200
Ice Age
What is a climate change that lowers temperatures of Earth?
200
ice core
What sample is used to determine Earth's historical climate changes?
300
Cretaceous
In what period did the dinosaurs became extinct?
300
amber, ice, and tar
What are materials that preserve original remains?
300
absolute age
What is the exact age of an item?
300
Oxygen
What is a gas produced during photosynthesis and required by humans to survive?
300
Silurian
What is the time when the first jawed fish appeared?
400
Quaternary
What is the time that humans are a part of?
400
sedimentary rock
What is the rock type most fossils are found in?
400
radioative dating
What is a way to determine absolute age?
400
uniformitarianism
What is the idea that Earth is always changing?
400
Triassic
What is considered to be the beginning of the reptile age?
500
Hadean, Archean, and Proterozoic
What eons make up the Precambrian?
500
footprints, animal holes, and feces
What are examples of trace fossils?
500
half-life
What is the length of time for half of the atoms of a radioactive element to decay?
500
oceans
What is the location of most life on Earth during the Paleozoic Era?
500
prokaryote
What is a single cell with no nucleus?
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