Lifecycle of Stars - Paper 1

Question 1

What is a nebula?

Answer 1

A cloud of dust and gas (primarily hydrogen)

Question 2

What is the first step of the lifecycle of a star?

Answer 2

Nebula

Question 3

Which step follows nebula in the lifecycle of a star?

Answer 3

Protostar

Question 4

Why does a nebula turn to a protostar?

Answer 4

Gravity pulls the dust and gas of a nebula together over time

Question 5

What causes a protostar to get bigger?

Answer 5

Attraction of yet more particles as its gravity increases

Question 6

State the name of the stage of stellar evolution that our Sun is in

Answer 6

Main Sequence

Question 7

How long can the main sequence stage of stellar evolution take?

Answer 7

Billions of years

Question 8

Which gas makes up most of a nebula?

Answer 8

Hydrogen

Question 9

Why is the main sequence stage of stellar evolution referred to as stable?

Answer 9

The inwards force due to gravity and the outwards force as a result of nuclear fusion are in equilibrium

Question 10

Describe what will happen to our Sun between the main sequence stage and the end of its stellar life cycle (3 marks)

Answer 10

The sun will expand to form a red giant
It will then eject its outer layers of gas to become a white dwarf
And when as the white dwarf cools, it will stop emitting light and become a black dwarf

Question 11

Describe the process of nuclear fusion in stars (3 marks)

Answer 11

Two small nuclei
join together to produce a larger nucleus
releasing energy (allow gamma radiation)