Absolute and Relative Dating Review M/J2

Front

What does the law of superposition state?

Back

In a sequence of undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest layers are at the top.

Front

What is the definition of half-life?

Back

The time it takes for 50% of the nuclei in a radioactive sample to decay to its stable isotope.

Front

What type of fossil is best for determining the age of rock layers?

Back

Index fossil.

Front

What percentage of the parent isotope remains after one half-life?

Back

50%.

Front

What is the original element that undergoes radioactive decay called?

Back

Parent element.

Front

What is an index fossil?

Back

A fossil that is used to define and identify a particular time period in the geological time scale.

Front

What is the daughter product in radioactive decay?

Back

The stable isotope that is formed after the parent isotope has decayed.

Front

How does radioactive dating work?

Back

It measures the amount of parent and daughter isotopes in a sample to determine its age.

Front

What is the significance of the half-life in geology?

Back

It helps geologists determine the age of rocks and fossils by measuring the decay of radioactive isotopes.

Front

What is a trace fossil?

Back

A fossil that provides evidence of the activity of ancient organisms, such as footprints or burrows.