Helloyo!
Massive Star
They are typically greater then 8 molar masses. They typically have a quick main sequence phase, a short red supergiant phase and a death of a spectacular Cosmic event: Supernova. From there they can either become Neutron Stars or Black Holes
Medium-Sized Star
They usually have a Normal Main Sequence phase (Billions of years). From there they bevome Red Giants and expell their mass in a planetary nebula. From there they shrink and become white dwarfs first, then black dwarfs.
Hope it helps ya
...though astronomy is actually physics btw...
Answer:
What impact do the available amounts of energy, water, and oxygen have on an ecosystem? They act as limiting factors. ... increasing the biodiversity of the ecosystem.
Africa, Australia, etc because they are the oldest ones.