A Trip Through Earth's History

Front

What is radioactive dating?

Back

A method used by geologists to determine the absolute ages of rocks by measuring the decay of radioactive isotopes.

Front

What does radioactive decay involve?

Back

The process where atoms of an unstable element break down to form atoms of another element.

Front

What is a fossil?

Back

The preserved remains or traces of an organism.

Front

How do most fossils form?

Back

Most fossils form when living things die and their remains are buried by sediments.

Front

What is a petrified fossil?

Back

A fossil formed when minerals replace all or part of an organism.

Front

What is the difference between relative age and absolute age?

Back

Relative age is the age of a rock compared to other rocks, while absolute age is the actual age of a rock.

Front

What are the main types of fossils?

Back

The main types of fossils include body fossils, trace fossils, molds, and casts.

Front

What is a mold fossil?

Back

A mold fossil is a cavity in rock that has the shape of an organism.

Front

What is a cast fossil?

Back

A cast fossil is a solid copy of the shape of an organism.

Front

What role do sediments play in fossil formation?

Back

Sediments help preserve the remains of organisms by burying them and preventing decay.