Question

Why do you have to we use carbon-14 to measure the half-life of a decaying tree?(1 point) Responses All once-living things contain uranium-238 and the amount begins to increase when the tree dies. All once-living things contain uranium-238 and the amount begins to increase when the tree dies. All once-living things contain carbon-14 and the amount begins to decrease when the tree dies. All once-living things contain carbon-14 and the amount begins to decrease when the tree dies. All once-living things contain uranium-238 and the amount begins to decrease when the tree dies. All once-living things contain uranium-238 and the amount begins to decrease when the tree dies. All once-living things contain carbon-14 and the amount begins to increase when the tree dies.

Answer 1

The correct response is: **All once-living things contain carbon-14 and the amount begins to decrease when the tree dies.**

Carbon-14 is a radioactive isotope that is present in the atmosphere and is absorbed by living organisms. When the organism dies, it no longer takes in carbon-14, and the existing carbon-14 begins to decay at a predictable rate. This allows scientists to measure the amount of carbon-14 remaining in a sample to estimate the time since the organism's death.