Question

the first four steps in the formation of the sun are listed below.
1. a cloud of gas and dust called nebula spins slowly.
2. the nebula collapse due to condensation of gases
3. the cloud spins faster as it collapses.
4. the contracting nebula flattens into a disk with a bulge at the center
which of these statements bet describe the next step in the formation of the sun?
gravitational forces pull the gases further away from the center of the disk.
nuclear fusion of gases takes place in the center of the nebula.

Answer 1

the gas particles in the center of the nebula repel each other and move apart
or
the nuclear fission of the gas molecules release large amount of energy

Answer 2

probably: nuclear fusion of gases takes place in the center of the nebula.

its because the heat of the star is made in the centre by nuclear fusion reactions.