Question

question 15
1 pts
why is there an upper mass limit for main - sequence stars of about 100 to 150 solar masses?
giant molecular clouds do not contain enough material.
general relativity does not allow such massive objects to exist.
objects above this mass fuse hydrogen too quickly & make too much radiation pressure and cannot stay together.
objects above this mass do form in molecular clouds; however, they emit no light and are not considered stars.
the rotation rate is so high that such an object splits into a pair of stars.

Explanation:

When a star is too massive (above about 100 - 150 solar masses), the rate of hydrogen fusion is extremely high. This leads to an enormous amount of radiation pressure being generated. The radiation pressure becomes so strong that it overcomes the gravitational force trying to hold the star together. As a result, the star cannot stay intact.
Giant molecular clouds can have enough material (so the first option is wrong). General relativity doesn't prohibit such massive objects in the context of star formation (second option wrong). Stars above this mass do emit light (fourth option wrong). Rotation rate causing splitting is not the main reason for the upper - mass limit (fifth option wrong).

Answer:

Objects above this mass fuse hydrogen too quickly & make too much radiation pressure and cannot stay together.