How many molecules exist in 50.0 grams of phosphorus trihydride

Substance a is a nonpolar liquid and has only dispersion forces among its constituent particles. substance b is also a nonpolar liquid and has about the same magnitude of dispersion forces among its constituent particles. when substance a and b are combined, they spontaneously mix.

In which of the following phases of matter do molecules have the highest amount of energy? a. liquid b. gel c. solid d. gas

Ahelium balloon contains 16.9 l of helium at stp. how many atoms of helium are in the balloon