which allows scientists to determine the Earth was at least 4.3 billion years old

Answer 1

The use of radiometric dating methods allows scientists to determine the age of rocks and minerals on Earth. By analyzing the ratio of radioactive isotopes to stable isotopes in these materials, scientists can calculate the amount of time that has passed since the rocks or minerals formed. This technique has been used to determine that the Earth is at least 4.3 billion years old.