Question

A rock on the oldest Hawaiian island is found to around 65

million years old when using two different dating techniques.
One group of scientists used Sm-146 and found about 95%
of the element had decayed over that time frame. A separate
group used potassium-40 and found only about 10% of the
potassium had decayed over that same time frame.
What is the reported age of the rock on the oldest Hawaiian island based on Sm-146 dating?
a) 65 million years
b) 95 million years
c) 10 million years
d) 146 million years

Answer 1

The reported age of the rock using Sm-146 dating is unclear from the provided options, as the question lacks necessary details like the half-life of Sm-146; however, if based on two dating techniques, the age is around 65 million years.

Step-by-step explanation:

The reported age of the rock on the oldest Hawaiian island based on Sm-146 dating cannot be determined accurately from the options provided (a) 65 million years, (b) 95 million years, (c) 10 million years, or (d) 146 million years, because there is insufficient information regarding the half-life of Sm-146 or the proportion of remaining Sm-146 to its decay product. Typically, isotopic dating methods require knowing the half-life of the parent isotope and the current ratio of parent to daughter isotopes to calculate the age of a rock sample.

However, if we are referring to the rock being found to be around 65 million years old by two different dating techniques as mentioned in the question, then option (a) 65 million years would be the correct answer. This detail is noteworthy but appears to contradict the information given specifically about the Sm-146 dating, suggesting there may be some confusion in the question as it stands.