Carbon-11 is a radioactive isotope of carbon. Its half-life is 20 minutes. What fraction of the initial number of C-11 atoms in a sample will remain after 80 minutes?

The graph indicates the running route for tobias. which best describes his run? from time 0 to 6, he went fast and then slowed down. from time 6 to 10, he was at his slowest. from time 12 to 14, he went very slow. from time 14 to 18, he went toward the starting point.