Which of the following measurements has 2 significant figures? 11.0 cm 100 cm

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

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.

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?