Calculate the mass of each element in the
compound by multiplying its molar mass by the
number of moles of the element present in one
mole of the compound.
mass N =
mass H =
mass O =

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium