A mixture of xe, kr, and ar has a total pressure of 6. 70 atm. What is the mole fraction of kr if the partial pressures of xe and ar are 1. 60 atm and 2. 80 atm, respectively.

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

Scientists observed a rock stratum with fossil. if mollusks evolved before arthropod, where will their fossils be found.

After studying french for 5 yearscin school, i was shocked to discover when i went to france that i couldn't even get a glass of water without a lot of sign language what is the author main point