Which dating method estimates a rock's age by comparing unstable to stable atoms?

Which dating method estimates a rock's age by comparing unstable to stable atoms?

• A. Relative dating
• B. Absolute dating
• C. Observations
• D. Evidence

Answer: (B)

Radiometric dating relies on radioactive decay, where unstable parent isotopes gradually transform into stable daughter isotopes over time. By measuring how much parent remains compared to how much daughter is present in a rock, scientists can calculate the time that has passed since the rock formed, using the known decay rate. This provides a numerical age, which is why it’s considered an absolute dating method. Relative dating, in contrast, only tells which rocks are older or younger than others, not their exact ages. Observations and evidence aren’t dating methods themselves, so they don’t yield a numeric age.

Radiometric dating relies on radioactive decay, where unstable parent isotopes gradually transform into stable daughter isotopes over time. By measuring how much parent remains compared to how much daughter is present in a rock, scientists can calculate the time that has passed since the rock formed, using the known decay rate. This provides a numerical age, which is why it’s considered an absolute dating method. Relative dating, in contrast, only tells which rocks are older or younger than others, not their exact ages. Observations and evidence aren’t dating methods themselves, so they don’t yield a numeric age.