Space

Question 1

Nebula

Answer 1

All stars form from a giant cloud of hydrogen gas and dust called a nebula

Question 2

Protostar

Answer 2

The force of gravity within a nebula pulls the particles closer together until it forms a hot ball of gas, known as a protostar
As particles pilled closer the density of the protostar will increase

Question 3

Main sequence star

Answer 3

Once the protostar becomes hot enough, nuclear fusion reactions occur within its core

Question 4

Thermal expansion from fusion reaction occur within its core due to fusion and the force of gravity keeps the star in equilibrium

Answer 4

Star forms and it becomes a main sequence star
During the main sequences the star is in equilibrium and said to be a stable

Question 5

Red giant

Answer 5

after several billion years the hydrogen causing the fusion reactions in the star will begin to run out
Fusion reactions in the core will start to die down
This causes the core to shrink and heat up
A new series of reaction will occur around the core
As the core shrinks more reactions will cause the outer part of the star to expand
It will become a red giant
It is red because outer surface starts to cool

Question 6

White dwarf

Answer 6

Star will eventually become unstable and eject the outer layer of dust and gas
The core which is left behind will collapse completely, due to the pull of gravity and the start will become a white dwarf
The white dwarf will be cooling down and as a result, the amount of energy it emits will decrease

Question 7

The brightness of star

Answer 7

The brighter the star the smaller the magnitude
The dimmer the star the bigger the magnitude