Question

question: if you need to date a rock sample from a layer of strata from 500 ka, which isotopic dating method should you use? answer options: select one of four uranium-lead dating strontium-rubidium dating potassium-argon dating carbon-nitrogen dating

Explanation:

1. Uranium - lead dating is used for very old rocks (millions to billions of years), not for 500 ka (thousand years ago) scale.
2. Strontium - rubidium dating has a long half - life and is used for older geological time scales (hundreds of millions to billions of years).
3. Potassium - argon dating has a half - life suitable for dating rocks from around 100 ka to billions of years. 500 ka falls within this range.
4. Carbon - nitrogen dating (carbon - 14 is more common, and carbon - nitrogen is not a standard isotopic dating method for rocks; carbon - 14 dating is for organic materials and has a limit of around 50 - 60 ka, so it's not suitable for 500 ka rock samples).

Answer:

Potassium - argon dating