What methods of dating do scientist use to study Earth's history? (Two part answer)

Researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

A.) Nitrogen

Explanation:

Nitrogen is also found in nucleic acid and proteins. ... Proteins, unlike carbohydrates and lipids, always contain nitrogen ... (I looked it up)