What aspect of carbon-14 makes it useful for dating organic materials?

Carbon-14 is particularly useful for dating organic materials primarily because it decays at a constant rate. This property is crucial for radiocarbon dating, which relies on the predictable half-life of carbon-14, approximately 5,730 years. As living organisms take in carbon-14 from the atmosphere, the ratio of carbon-14 to carbon-12 remains relatively stable during their life. Once the organism dies, it no longer takes in carbon-14, and the isotope begins to decay at this consistent rate. Scientists can measure the remaining amount of carbon-14 in a sample and determine how long it has been since the organism died based on the established decay rate. This method allows for dating materials that are thousands of years old, making carbon-14 a valuable tool in archaeology and other fields.

In contrast to this correct answer, other aspects mentioned in the choices do not provide the same utility for dating. Stable isotopes do not decay and therefore do not assist in dating organic materials. A high atomic mass is not relevant to the dating capability of carbon-14, and being non-radioactive would mean the isotope cannot undergo decay, which is essential for this dating process.