What type of object in the galaxy could you study to investigate whether stars consist primarily of helium or hydrogen

Explanation:

To determine the composition of the star,  scientists takes the help of the atomic physics .  

As Different ions or atoms emits light waves at different combinations of wavelength that is particular of that very atom or element . These light waves are knows as the emission lines and each atom or ion has unique emission spectra which allows them to distinguish which kind of element light is sent out from the star and hence distinguish whether the star is made up of hydrogen or helium .  

i believe that if you say you can, you cant and if you say you can't your right. i believe i can do anything i set my mind to. i've applied this with my everyday life. it me get motivated to do stuff.for example, i apply this to do school. if i believe i can finish a whole class in a couple of week's i will be motivated to do the class until i finish it, and if i believe i can't, i will get distracted and do other stuff besides doing my work. it changed me by believing i can accomplish anything i set my mind to.

the correct answer would be true friction causes the faults to slip or collide