A combustion analysis is done on 522.4 grams of an unknown substance. The analysis produces 499.4 g of carbon dioxide and 204.5 g of water. There are no other products. What is the empirical formula of the unknown substance?

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.