B. A uranium-238 is used to determine the age of an unearthed rock. It was found out that the rock contains 25% Lead-206 in proportion to urarium-238, What is the absolute age of the rock?
The half - life of U 238 is about 4.5 billion years. As time passes, the ratio of Pb 206 to U 238 will increase and it is this which enables the age of the rock to be estimated
