6. a rock sample contained 10 grams of k - 40 when it solidified, but now contains only 5 grams of k - 40. k…

6. a rock sample contained 10 grams of k - 40 when it solidified, but now contains only 5 grams of k - 40. k - 40 is an isotope of potassium (k) with a half life of 1.3 billion years. what is the age of the rock?\n5700 years\n2.6 billion years\n1.3 billion years\n4.5 billion years
Answer
Explanation:
Step1: Understand half - life concept
The amount of a radioactive substance reduces by half in one half - life.
Step2: Analyze the change in K - 40 amount
The rock sample started with 10 grams of K - 40 and now has 5 grams. The amount of K - 40 has reduced by half.
Step3: Determine the age of the rock
Since the amount of K - 40 has reduced by half, and the half - life of K - 40 is 1.3 billion years, the age of the rock is equal to one half - life of K - 40.
Answer:
1.3 billion years