A radioactive isotope has a half -life of 1.2 billion years . As measured by the presence of the
Channel: Doubtnut
Date: 2020-05-10

A radioactive isotope has a half -life of 1.2 billion years . As measured by the presence of the isotope and its stable decay producy ,a rock originally contains 10g of the radioactive isotope and now contains 1.25 g . How many  years old is the rock?