What tests were able to determine when continental crust was formed? a. potassium-argon dating and half-life isotopes b. relative dating and carbon-prototyping c. stratigraphic measurement and argon-aluminum dating d. stratigraphic measurement and strontium-rubidium dating

The correct answer is A. Potassium-argon dating and half-life isotopes

Explanation:

Potassium-argon dating and half-life of an isotope is the only method to determine the ancient archaeological objects beneath the earth's surface.

According to geologists the age of rocks dates back to 4 billion years. These facts are based on the radioactive isotopes of potassium (K-40). This isotope, after its half-life, decays into argon gas (Ar-40).

The comparison of the amount of the isotopes K-40 to Ar-40 gives the information about the time period the rock has formed. This method is quite useful for paleoanthropologists and archaeologists to study human evolution.

Option A, Potassium-argon dating and half-life isotopes

Explanation:

Dating helps in determining the age of old rocks.The age of continental crust is determined by calculating the final weight of rock as compared their initials weight.

The formula for determining the age is as follows -

Where N is the final weight of the radioactive substance with in the  continental crust.

is the initial weight of the radioactive substance with in the  continental crust.

K is the rate constant and

t is the

Hence option A is correct

i think the answer is b.