/hich allowed scientists to determine that Earth was at least 4.3 billion years old? (1 point)
The discovery of radioactive decay in rocks and minerals allowed scientists to determine that Earth was at least 4.3 billion years old.
The discovery of radioactive decay in rocks is what allowed scientists to determine that Earth was at least 4.3 billion years old. By studying the decay of radioactive isotopes within rocks, scientists were able to calculate the age of the Earth.
The scientific method of radiometric dating allowed scientists to determine that Earth is at least 4.3 billion years old. Radiometric dating is based on the principle that radioactive isotopes decay at a constant rate over time. By studying the decay of certain isotopes in rocks and minerals, scientists can calculate how old they are.
One commonly used radiometric dating technique is called uranium-lead dating. Uranium-238 decays into lead-206 at a known rate, so by measuring the ratio of uranium to lead in a sample of rock, scientists can determine its age. This method is particularly useful for dating rocks that are billions of years old.
Another technique called potassium-argon dating is used to determine the age of volcanic rocks. Potassium-40, a radioactive isotope, decays into argon-40, and by measuring the ratio of potassium to argon in a rock sample, scientists can calculate its age.
These radiometric dating methods have been widely used to determine the age of Earth's oldest rocks and minerals, such as those found in Greenland and Western Australia, which have been dated to be over 4.3 billion years old. This provides strong evidence for the age of Earth being at least 4.3 billion years.