Question

1. compare: review the scales you made.

a. how do the stars luminosity compare with their radii?
in general, the larger a star is, the it is.
b. how do the stars radii compare mass?
in general, the larger a star is, the it is.

Explanation:

For part A, according to the Stefan - Boltzmann law \(L = 4\pi R^{2}\sigma T^{4}\) (where \(L\) is luminosity, \(R\) is radius, \(\sigma\) is the Stefan - Boltzmann constant, and \(T\) is temperature). If we assume similar surface temperatures (a reasonable assumption when just comparing size effects in a general sense for stars of similar types), a larger radius (\(R\)) leads to a larger luminosity (\(L\)). So the larger the star (larger \(R\)), the brighter (larger \(L\)) it is.

For part B, in general, more massive stars tend to be larger. There is a mass - radius relationship for main - sequence stars (and other stellar types to some extent). As mass (\(M\)) increases, radius (\(R\)) also increases for stars in certain evolutionary stages.

Answer:

A. brighter
B. more massive