explain radiometric dating fossils and rocks
{"Image DocumentName": "Fossil Record Radiometric dating uses the known time of natural decay of unstable isotopes to calculate the age of the material.", "Image ImageDescription": "Relative dating estimates the age of fossils by comparing the fossils found in certain rock layers to those in other layers. The oldest fossils are found on the bottom, further from the surface. The youngest fossils are closest to the surface.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}