Iodine-131 is a radioactive isotope with a half-life of 8 days. how many grams of a 64 g sample of iodine-131 will remain at the end of 24 days?

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d