Which type of star is most luminous

Choose all the answers that apply. ionic compounds dissolve easily in water do not dissolve in water have low melting points have high melting points conduct electricity when melted

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.

What is the percentage of hydrogen in nitrogen trihydride