Earth Science Unit 4 Review - Geologic Age

Front

What is the oldest layer in geological terms?

Back

Layer B is the oldest.

Front

In which time period did jellyfish first appear?

Back

Jellyfish first appeared in the Precambrian period.

Front

What is the process called when Earth elements decay and change into another element?

Back

The process is called radioactive decay.

Front

Which type of fossil is considered the best index fossil?

Back

The frog is considered the best index fossil.

Front

What is the term for the amount of time it takes for half of the atoms in a sample of a radioactive element to decay?

Back

The term is half-life.

Front

Define 'index fossil'.

Back

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

Front

What is the significance of the Precambrian period in Earth's history?

Back

The Precambrian period is significant because it covers the majority of Earth's history and includes the formation of the Earth and the appearance of the first life forms.

Front

Explain the concept of 'radiometric dating'.

Back

Radiometric dating is a method used to date materials by comparing the abundance of a radioactive isotope to its decay products.

Front

What does 'absolute age' refer to in geology?

Back

Absolute age refers to the actual age of a rock or fossil, often determined through radiometric dating.

Front

What is a 'fossil record'?

Back

The fossil record is the history of life on Earth as documented by fossils, showing the progression of species over time.