Geologic History unit Review

Front

What is a daughter isotope?

Back

A daughter isotope is the new atom that is formed when a radioactive atom undergoes decay.

Front

What are the two main traits of the best index fossils?

Back

The best index fossils are widespread geographically and have a short lifespan.

Front

Which fossil is considered the best index fossil?

Back

Fossil 2 is considered the best index fossil.

Front

What is the half-life of iodine-131?

Back

The half-life of iodine-131 is 8 days.

Front

Which two layers are the same age in geological terms?

Back

Bottom North and Middle West layers are the same age.

Front

Define half-life in the context of radioactive decay.

Back

Half-life is the time required for half of the radioactive atoms in a sample to decay.

Front

What is an 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

Why are short-lived fossils useful as index fossils?

Back

Short-lived fossils are useful as index fossils because they provide a more precise time frame for the age of the rock layers.

Front

What is the significance of widespread fossils in geology?

Back

Widespread fossils indicate that the organism lived in many different environments, making them useful for correlating the age of rock layers across large areas.

Front

What does it mean if two rock layers are said to be 'contemporaneous'?

Back

If two rock layers are contemporaneous, it means they were formed at the same time.