Question

This chart show the amount of radioactivity measured from three unknown isotopes.


Which statement describes each of the isotopes?

Isotope A was measured at day 24, Isotope B was measured at day 6, and Isotope C was measured at day 10.
Isotope A was measured at day 18, Isotope B was measured at day 4, and Isotope C was measured at day 5.
Isotope A was measured at day 24, Isotope B was measured at day 8, and Isotope C was measured at day 20.
Isotope A was measured at day 30, Isotope B was measured at day 6, and Isotope C was measured at day 10.

Answer 1

I don’t see the chart/image or the numerical values — I need that to pick the correct choice. Could you either upload the chart image or paste the data points (activity vs. time) for isotopes A, B and C?

If you want to check it yourself, here's how to decide which statement is correct:

1. For each isotope, read off the activity at two times (or find the time it takes for the activity to fall to half its initial value). That time is the half‑life (t1/2).
2. Use the decay law A(t) = A0·(1/2)^(t/t1/2) if needed to estimate t1/2 from any pair of values:
t1/2 = t · [log(1/2) / log(A(t)/A0)].
3. Compare the half‑lives (or the times shown in the multiple‑choice options) to the values in the four answer choices and pick the match.

If you upload the chart or paste the numbers, I’ll calculate the half‑lives and pick the correct statement for you.