What has the study of fossils allowed scientists to do?
Earth’s earliest atmosphere lacked which gas that is necessary for life as
The relative age of a rock is
Geologists use radioactive dating to
What are fossils?
The time it takes for half of the radioactive atoms in a sample of a radioactive element to decay is the element’s
What does the principle of uniformitarianism state?
What change in Earth's atmosphere allowed organisms to live on land.
Fossils usually occur in metamorphic rock.
The law of superposition helps geologists determine the absolute age of a rock layer.
Geologists divide Earth’s long history into smaller units called eras and periods that make up the geologic time scale.
Sometimes layers of rock are overturned so much that the youngest rock layer may appear on the bottom, which is the reverse of what is ordinarily expected.
Most fossils form from animals or plants that once lived in or near quiet water such as swamps, lakes or shallow seas where sediment builds up.
Extinction of a type of organism occurs when the environment changes and the organisms can not survive and reproduce in the changed environment.
Around 1896, Marie Curie was involved in the discovery of radioactivity.
Radioactive elements always decay at the same rate.
Carbon-14 is a non-radioactive form of carbon.
Scientists have determined that the Earth is about 4.6 billion years old.
Scientists developed the Geologic Time Scale by studying rock layers and index fossils.
Name the earliest form of life known on Earth.
Describe what scientists can learn about the past while studying fossils. Please use complete sentences.
Compare and contrast molds, casts, and trace fossils.
In the beginning, why was there no liquid water on Earth?
In detail, tell me how scientists think the Earth was formed. What processes happened? Please include the formation of oceans and continents in your answer as well. Please use complete sentences.
How do layers B and D compare in age? If rock layers between B and D have eroded away, what is the boundary between B and D called?
Layer F is an igneous extrusion. How could a geologist use layer F to infer the age of layer A?
