Question

about 90 percent of stars on the h-r diagram are _____ stars.
red giant
main sequence
supergiants
luminosity

Explanation:

The H - R (Hertzsprung - Russell) diagram is a key tool in astronomy (a subfield of Natural Science, specifically Physics when studying stellar properties). About 90% of stars on the H - R diagram are main sequence stars. Main sequence stars are in the phase where they fuse hydrogen into helium in their cores, and this phase is the longest and most stable phase of a star's life cycle, so the majority of stars are in this stage.

Answer:

main sequence