2.50 dm3 of an unknown gas had a mass of 4.17 g at 18 c and pressure of 101 kpa calculate the relative molecular mass of the gas (R=8.31)​

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