Radioactive dating is more accurate than relative dating because
Geologists often need to know the age of material that they find.They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in number of years.When ‘parent’ uranium-238 decays, for example, it produces subatomic particles, energy and ‘daughter’ lead-206.Isotopes are important to geologists because each radioactive element decays at a constant rate, which is unique to that element.For example, carbon dating is used to determine the age of organic materials.
Basically, fossils and rock found in lower strata are older than those found in higher strata because lower objects must have been deposited first, while higher objects were deposited last.
The atoms of some chemical elements have different forms, called isotopes.
These break down over time in a process scientists call radioactive decay.
Relative dating helps determine what came first and what followed, but doesn't help determine actual age.
Radiometric dating, or numeric dating, determines an actual or approximate age of an object by studying the rate of decay of radioactive isotopes, such as uranium, potassium, rubidium and carbon-14 within that object. This rate provides scientists with an accurate measurement system to determine age.