What percentage of the sun is composed of hydrogen?

How many atoms are in 1.4 mil of phosphorus trifluoride (pf3)

0.2348 grams of pbcl2 used to form 44.0 ml of solution.

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.