which property of argon makes it useful for potassium - argon dating?\nit decays into potassium.\nit is an…

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

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

Answer

Brief Explanations:

Potassium - argon dating is based on the fact that when potassium - 40 decays, it forms argon - 40. Argon is a gas. In the context of this dating method, argon remains trapped in rock. This allows scientists to measure the amount of argon that has accumulated over time (due to the decay of potassium) within the rock.

  • The first option is incorrect because it is potassium that decays (a small percentage of potassium - 40 decays into argon - 40, not the other way around).
  • The second option is wrong as argon (the isotope used in this dating, argon - 40) is a stable element.
  • The fourth option is incorrect. Potassium - argon dating is useful for dating old rocks (because the half - life of potassium - 40 is long, about (1.25\times10^{9}) years).

Answer:

It remains trapped in rock.