Calculate the mass in grams for 0.251 moles of Na2CO3

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

How do dying stars contribute to the formation of planets

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?