Question

why are spectral lines useful in classifying stars? (1 point)

they indicate a star’s age.

they show a star’s location.

they show the layers that make up a star.

they show the composition of a star.

Explanation:

Spectral lines are unique "fingerprints" created when elements in a star's atmosphere absorb or emit specific wavelengths of light. Each element produces a distinct pattern of spectral lines, allowing astronomers to identify the chemical components that make up the star. The other options are incorrect: spectral lines do not directly indicate a star's age, show its location, or reveal its internal layers.

Answer:

D. They show the composition of a star.