Help please! I will give brainliest if you get the correct answer An astronomer examines an emission line spectrum for a star from data recorded by a spectroscope. There are four lines: two in the blue region, one in the green region, and one in the red region of the spectrum. How does the spectrum obtained from the spectroscope help the astronomer?

A. It helps the astronomer determine that there are 4.32 light years between the star and the Sun.

B. It helps the astronomer determine that the star is two times larger than its neighboring star.

C. It helps the astronomer determine that the star is made mostly of hydrogen.

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)

option number c is the right answer.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.