A substance X2Z has the composition (by mass) of 40.0% X and 60.0 % Z. What is the composition (by mass) of the compound XZ2

Which of the dna typing techniques do you think you would choose if you had to analyze a dna sample? why?

Which of the following would have less momentum than a 52 kg cheetah running at 10 m/s?

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms