Earth Science 2Q, 1

Match it! Select the correct answer from the pull down...Good luck!

A bone sample contains only 1/4 of its original radioactive C14 content. The half-life of C14 is 5700 years. What is the age of the bone sample?

The visible lines on a map or graph that extend left to right are called:

Where did the oxygen in Earth's atmosphere come from?

The visible lines that extend up and down on a globe or map are called:

Animal life became possible on Earth after -

Graphs make it easier to understand data by making it:

Human activities (transportation, factories, etc.) are responsible for the INCREASE of which of these gasses?

The use of certain aerosols and refrigerants have caused a DECREASE in which of these gasses (this gas protects us from harmful UV radiation)?