HALF LIFES CHEMISTRY PROBLEMS
1)How much of a 888lb sample of Radium-189 Remains after 3 half Lives?

2)If you start with 200g or Uranium-282,How much will remain of 4 half lives?

3)How much of a 750 gram sample of 42K is left after 12.4 hours?

4)How much of an 88 gram sample of 232Th of remains after 4.2x10^10 years?

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm