the best way to determine that star 2 is the hottest is due to the fact that its intensity is generally higher than the intensity values for the other two stars. b. all three of these stars share at least some of the same types of atoms since some of the spectral absorption lines occur at the same wavelengths. c. the absorption lines come from cooler atoms in the outer layers of the star that use the star’s light to de-excite their electrons to lower energy levels.