In the formation of alum, why is it appropriate to wash the sides of the
beakers/flasks with distilled water?
A. Extra water will evaporate away when the alum
crystals are formed.
B. Distilled water has potassium ions that are
needed to form the alum.
C. The alum is not soluble in water.

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.