What chemical formulas represents oxygen gas? ?

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

Which is true of a liquid? it has a definite volume but not a definite mass.it has a definite mass but not a definite volume.it has a definite volume but not a definite shape.it has a definite shape but not a definite volume.

What type of reaction fuels the processes seen here?