The Life Cycle Of Stars

Question 1

when does a star form

Answer 1

when huge bodies of dust and gas collapse into itself due to its own gravity

Question 2

process of a star forming

Answer 2

• clouds of diffused gas (nebulas) in space
• force of gravity pulls a nebula together making a protostar
• heat and pressure build at the core of protostar
• nuclear fusion begins to take place
• hydrogen atoms fuse together generating alot of energy
• fusion of H atoms causes star to shine
• start eventually runs out of fuel and expands into a red giant or red super giant
• what happens next depends on the size of the star

Question 3

what happens to small to medium stars after the red giant stage

Answer 3

• they expand into a shell of gas leaving a white dwarf at the core
• turn black when energy is emitted

Question 4

what happens to a large star after the red super giant phase

Answer 4

• it explodes into a supernova leaving a neutron star as the core
• the biggest stars leave black holes

Question 5

why do some stars have different endings in the life cycle

Answer 5

because of their mass

Question 6

how does a star become a black hole

Answer 6

• when the core collapses before a supernova, the mass of the core is compressed into such a tiny point in space
• that much mass squeezed so tightly makes its gravitational pull so powerful that light cant escape it, so it looks black

Question 7

why does a core collapse when its energy runs out

Answer 7

• there was originally a delicate balance between gravity compressing it and radioactive energy expanding it
• this kept its volume constan
• however, when the star runs out of fusion energy the radioactive energy decreases and gravity wins the fight

Question 8

what can bigger stars do that small ones cant

Answer 8

fuse hydrogen into heavier elements up to iron, because of more heat and pressure at the core

Question 9

why does the core collapse, due to what its composed of

Answer 9

• because iron cant fuse into anything else
• it builds up at the core until fusion energy is too little from the star
• gravity overpowers it and the core implodes

Question 10

why does the star expand into a red giant

Answer 10

• the star gets compressed until its core is so hot and the pressure is so high that it causes the outer layers to expand
• its red because the surface cools