38. How many formula units (f. un) will 88.36 g of magnesium sulfide (MgS) contain? a. 4.71 x 10-21 f. un of MgS
c. 9.43 x 1023 f. un of MgS
b. 8.28 x 10-21 f. un of MgS
d. 1.66 x 1024 f. un of MgS

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.