Suppose that we have a sample of 20 atoms of radioactive potassium which decays by half every 1.3 billion years into calcium and argon at ratios of 9:1, respectively. How many atoms of calcium do you expect to find in this sample after 1.3 billion years?

Question

Quizplus · Accepted Answer

After 1.3 billion years, half of the 20 potassium atoms will have decayed, leaving 10 atoms. Of these 10 decayed atoms, 90% will become calcium, resulting in 9 calcium atoms.

Suppose That We Have a Sample of 20 Atoms of Radioactive