A parent isotope of rubidium-87 undergoes radioactive decay. If there were 50,000 atoms of the parent isotope initially, how many atoms of the parent isotope would be there after the 3^rd half-time of decay? 6250 1250 o 6500 1225

## Step 1: Understanding the Problem### The problem pertains to the radioactive decay of rubidium-87. The half-life of a radioactive substance is the time taken for half of its atoms to decay.## Step 2: First Half-Life Calculation### After one half-life, half of the initial number of atoms would remain undecayed. Therefore, after the first half-life, we calculate the remaining atoms as: So, 25000 atoms would remain undecayed after the first half-life.## Step 3: Second Half-Life Calculation### After the second half-life, half of the 25000 atoms would decay, leaving: So, 12500 atoms would remain undecayed after the second half-life.## Step 4: Third Half-Life Calculation### After the third half-life, half of the 12500 atoms would decay, leaving: So, 6250 atoms would remain undecayed after the third half-life.## Step 5: Conclusion### Thus, after the third half-life of decay, 6250 atoms of the parent isotope would remain.#