X-245 has a half-life, measuring in 8.5 hours. If you have a 2500 gram sample of this substance, how long will it take until you only have 1 gram sample remaining? (answer in hours)

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.