(3)After the protostar gets hot enough nuclear fusion reactions fuse together helium and hydrogen
(4)A main sequence star is?
A. A star that shines steadily due to nuclear fusion
B. Several stars close together
C.A star with planets orbiting
D. A Nebula that skips a protostar and is instantly turns into a star.
(5)The bigger the star the longer it will live
(6)What happens when a star the size of our sun runs out of Hydrogen?
A. It uses helium as fuel
B. It uses carbon as fuel
C. It goes supernova instantly
D. It turns green
(7)Stars the size of our sun swell to a blue super giant after they run out of fuel.