Geology Quiz

Identify the approximate age of the Earth in years.

• 46 million

• 4.6 million

• 46 billion

• 4.6 billion

An example of relative dating would be

• determining the minerals that make up a rock

• placing rock layers in order from youngest to oldest

• classifying rocks by type

• using radioactive isotopes to determine the exact age of rock samples

An example of absolute dating would be

• determining the minerals that make up a rock

• placing rock layers in order from youngest to oldest

• classifying rocks by type

• using radioactive isotopes to determine the exact age of rock samples

The half life of a radioactive isotope is the amount of time it takes for half of the total parent isotopes in a sample to decay into daughter isotopes.

• True

• False

Identify the correct order of the divisions of the geologic time scale from largest to smallest.

• period, eon, era, epoch

• eon, epoch, era, period

• epoch, period, era, eon

• eon, era, period, epoch

An organism that lived for a short time, over a widespread area, and had very distinct features might make a good ____.

• index fossil

• body fossil

• trace fossil

• impression fossil

How do scientists determine where to put the divisions in the Geologic Time Scale?

• There is a set number of years for each division.

• The divisions are made every time a volcano erupts.

• The divisions are made when the Earth undergoes a major change in its climate, life, or geography.

• The divisions are made only when a new species develops.

What percentage of the radioactive isotope will be left after 3 half lives?

• 50%

• 25%

• 12.5%

• 6.25%

All Eras throughout Earth history have lasted the same number of years.

• True

• False

Radiometric dating is possible because the rates of decay of radioactive isotopes ____.

• change over time

• vary from place to place

• change randomly

• are consistent