Answer:
The radioactive dating method is one of the efficiently used methods in order to calculate the age of the rocks, meteorites, fossils and various other objects, depending upon the rate at which radioactive isotopes decay. In this method, an unstable element changes into a stable one, releasing some amount of radiation and losing a certain amount of energy.
This is efficient in determining the age of the earth. The earth is comprised of rocks that are present from the time of its formation. These rocks can be dated using this method and the approximate age of the rock is evaluated.
The Uranium-Lead dating (²³⁸U-²⁰⁶Pb) method was used to date the smaller zircon crystals of Australia that are about 4.4 billion years old. The half-life of U-238 is approximately 4.5 billion years, which shows that these are one of the oldest rocks on earth and helps in understanding how old the earth is.
Half-life is defined as the time required by a radioactive isotope to decay half of its atoms.
So the radioactive dating method is one of the common method gives the approximate age of the earth.