P1 - Topic 3 - Life Cycle Of Star

Question 1

What do stars initially form as?

Answer 1

Nebulas - a cloud of gas and dust

Question 2

How does gas and dust spiral together?

Answer 2

The force of gravity

Question 3

What does the force of gravity do to a nebula?

Answer 3

Pull together the dust and gas

Question 4

What causes the temperature of a nebula to rise?

Answer 4

The gravitational energy being converted into heat energy

Question 5

When the temperature gets higher enough what happens to hydrogen nuclei?

Answer 5

It undergoes thermonuclear fusion to form helium nuclei and give out massive amounts of energy

Question 6

When a hydrogen nuclei undergo thermonuclear fusion, what is formed and given out?

Answer 6

A helium nuclei is formed and gives out massive amount of energy

Question 7

How is a star born?

Answer 7

1) the force of gravity creates a nebula by pulling tigers he dust and gas
2) gravitational energy is converted into heat energy
3) when the temperature rises enough, hydrogen nuclei undergo thermonuclear fusions to form a helium nuclei and give out massive amounts of energy

Question 8

When a star is born what dos it immediately enter?

Answer 8

It enters a long stable period where the heat create by nuclear fusion provides an outward pressure to balance the force of gravity pulling everything inwards

Question 9

What is a star called when it enters a long stable period and how long does it last?

Answer 9

Main sequence star and it can last for several billion years

Question 10

What is a nebula?

Answer 10

A cloud of dust and gas

Question 11

In the core of a star, what eventually runs out?

Answer 11

Hydrogen

Question 12

What happens what the hydrogen in the core of a star begins to run out?

Answer 12

The star swells into a red giant

Question 13

Why does a red giant star become red?

Answer 13

Because the surface cools

Question 14

How does a red giant star form?

Answer 14

When a main sequence star eventually begins to run out of hydrogen in the core, it swells into a red giant

Question 15

The the sun a bit or small star?

Answer 15

Small

Question 16

After becoming a red giant star, what kind of star does it become?

Answer 16

Planetary nebula and white dwarf

Question 17

How does a red giant become a planetary nebula?

Answer 17

It becomes unstable and ejects layers of dust and gas as a planetary nebula

Question 18

Does a a white dwarf eventually disappear?

Answer 18

Yes

Question 19

Why does a white dwarf eventually disappear?

Answer 19

Because it cools down

Question 20

What is a white dwarf star?

Answer 20

A hot dense solid core that is left behind when a small star becomes unstable and ejects its outer layers of dust and gas

Question 21

What do big stars become after a red giant?

Answer 21

A supernova star

Question 22

How does a supernova from?

Answer 22

They undergo more fusion and expand and contract server all times, forming heavier elements in various nuclear reactions. Eventually they’ll explode in a supernova

Question 23

If a star is big enough what will it become after a neutron star?

Answer 23

A black hole

Question 24

When do black holes form?

Answer 24

When the star is big enough to become one

Question 25

What is a neutron star and how is it formed?

Answer 25

It is a very dense core which is left after an exploding supernova throws the outer layers of dust and gas into space

Question 26

What is the life cycle of a big star?

Answer 26

Nebula 
Main sequence star 
Red giant 
Supernova 
Neutron star 
Black hole (if big enough)

Question 27

What is the life cycle of a small star?

Answer 27

Nebula 
Main sequence star 
Red giant 
Planetary nebula 
White dwarf