1. The first stage of stellar formation is the assembly (or formation) of a . 2. Stars form in clouds. 3. When a cloud collapses it into smaller and smaller pieces till those pieces reach stellar masses. 4. As the density increases, the fragments become , which the temperature of the cloud and inhibits further fragmentation. 5. The then condense into rotating globs of gas that serve as stellar embryos. 6. During this stage the surface temperature and luminosity despite decreasing size. 7. The central temperature and pressure increase as the potential energy is converted to energy due to contraction.

The keywords to input into the blank spaces were omitted which are ; fragments, increases, decreases, opaque, raises, molecular, protostar, gravitational, thermal.

Please find the answers for the blank spaces in the explanation column

Explanation:

1. The first stage of stellar formation is the assembly (or formation) of a_PROTOSTAR . 2. Stars form in MOLECULAR clouds. 3. When a cloud collapses, it FRAGMENTS into smaller and smaller pieces till those pieces reach stellar masses. 4. As the density increases, the fragments become_OPAQUE , which___RAISES the temperature of the cloud and inhibits further fragmentation. 5. The __FRAGMENTSthen condense into rotating globs of gas that serve as stellar embryos. 6. During this stage the surface temperature INCREASES and luminosity__INCREASES despite decreasing size. 7. The central temperature and pressure increase as the GRAVITATIONAL potential energy is converted to energy due to THERMAL contraction.

The above describes the evolution or formation of stars which begins with the collapse of a molecular cloud by gravitational force, this collapse cause the molecular cloud to fragment with the release of heat --Gravitation potential energy causing an increased temperature and pressure of the newly condensing  fragment with increasing luminosity known as a Protostar.