Q. With reference to Uranium-Thorium-Lead Dating, consider the following statements;
1.In this the radioactive isotope decays into argon and their ratios can give a clue about the age of rocks.
2.The ratios of these elements present in the material can be measured and used to make estimates about age.
Which of the statements given above is/are correct?

[A] .1 only

[B] 2 only

[C] .Both 1 and 2

[D] Neither 1 nor 2

Answer: B
Notes:

Statement 1 is incorrect: Uranium and Thorium have several radioactive isotopes, and all of them decay into the stable lead atom.

Statement 2 is correct: The ratios of these elements present in the material can be measured and used to make estimates about age.

Source: Carbon Dating