The graph below shows the radioactive decay of an isotope of uranium. Bar graph showing time in millions of years on x axis and number of uranium atoms present on y axis. Height of bar corresponding to time 0 million years is 100; time 4500 million years is 50; time 9000 million years is 25; time 13,500 million years is 12.5; and time 18,000 million years is 6.25.

Based on the graph, what is the half-life of uranium?

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous