some elements are unstable. their atoms give off particles over time at specific and constant rates. when…

some elements are unstable. their atoms give off particles over time at specific and constant rates. when molten rock cools to form igneous rock, some radioactive atoms are trapped. by using the rate of decay and looking at how many unstable atoms are left, scientists can estimate when that rock was formed. thats called radiometric dating. sedimentary rocks, where fossils are usually found, can only be dated this way if they are younger than 50,000 years old. but imagine a fossil found between layers of volcanic ash. scientists could use radiometric dating for the layers above and below the fossil. then, according to the law of superposition, they would know that the fossils age is somewhere within that range. based on the passage, when is radiometric dating possible? a when a substance is made of unstable atoms b when a substance contains a fossil c when the mass of a fossil is unknown d when relative dating will not work

some elements are unstable. their atoms give off particles over time at specific and constant rates. when molten rock cools to form igneous rock, some radioactive atoms are trapped. by using the rate of decay and looking at how many unstable atoms are left, scientists can estimate when that rock was formed. thats called radiometric dating. sedimentary rocks, where fossils are usually found, can only be dated this way if they are younger than 50,000 years old. but imagine a fossil found between layers of volcanic ash. scientists could use radiometric dating for the layers above and below the fossil. then, according to the law of superposition, they would know that the fossils age is somewhere within that range. based on the passage, when is radiometric dating possible? a when a substance is made of unstable atoms b when a substance contains a fossil c when the mass of a fossil is unknown d when relative dating will not work

Answer

Brief Explanations:

The passage states that radiometric dating uses the decay rate of unstable atoms. So it's possible when a substance has unstable atoms. Fossils are just an example related to dating in context, mass - of - fossil is not relevant, and relative dating not working is not mentioned as a condition for radiometric dating.

Answer:

A. when a substance is made of unstable atoms