Multiple Choice
An ancient rock is found to contain 40Ar gas,indicating that 
of the 40K in the rock has decayed since the rock solidified.Any argon would have boiled out of liquid rock.The half-life of 40K is 1.25 billion years.How long ago did the rock solidify?
A) 2.6 billion years
B) 0.50 billion years
C) 1.8 billion years
D) 0.30 billion years
Correct Answer:
Verified
Correct Answer:
Verified
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