How many molecules of water are there in one mole of h2o

what is the density of an object that has a mass of 10 g and a volumeof 5 ml? a. 0.5 g/ mlb. 2 g/mlc. 15 g/ mld. 50 g/ ml

What is a property of a double replacement reaction

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