An initial sample of iridium-192 is prepared pure, with no contamination of other isotopes. After a certain amount of time, one finds that the sample includes 4.4% osmium-192. How much times has passed since the initial sample was prepared? (Hint: Use what you know about half life to create a proportion. 50% of the sample would decay in one half life, so how long would it take for 4.4% o the sample to decay?)

Which statement is true according to the kinetic theory? a. molecules of different gases with the same mass and temperature always have the same average density. b. molecules of different gases with the same mass and temperature always have the same average volume. c. molecules of different gases with the same mass and temperature always have the same pressure. d. molecules of different gases with the same mass and temperature always have the same molecular mass. e. molecules of different gases with the same mass and temperature always have the same average kinetic energy.