Radioactive dating is used to determine the age of fossils.
Radioactive dating requires the use of a decay curve.
A decay curve is used to determine the age of fossils.
What is used to determine the age of fossils?

  - Calcium carbonate
  - dinosaurs
  - a barometer
  - electron microscope
  - a thermometer
  - a decay curve
  - chemical equations
  - Physical weathering