Unfortunately, I am not one for science, but I can try to answer some of these -
1). A large mass of gas and dust. Stars are “born” from these.
3). Smaller stars live longer. The larger a star is, the faster it’ll burn out.
4). The phase the stars spend most of their lives in.
6). No - stars are put into groups based upon their luminosity and temperature. Also, the lives of stars take different turns.
I hope this helps a bit :)
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