If you start with 20 kg of a radioactive isotope, calculate how much of the original isotope is left after one half-life has elapsed? Write your answer in decimal kg, and as a fraction of the original.

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.