Question

which property of argon makes it useful for potassium - argon dating? it decays into potassium. it is an unstable element. it remains trapped in rock. it is useful only for dating newer rock.

Explanation:

In potassium - argon dating, argon is the daughter product of the radioactive decay of potassium. Argon is a gas that remains trapped in rock after it forms from the decay of potassium over time, which helps in dating rocks.

Answer:

It remains trapped in rock.