GCSE Life Cycle of a star

What causes a cloud of dust and gas in space to start collapsing? (Choose two)

• Its own gravity

• Solar winds

• A nearby star exploding in a supernova

• Black hole's gravity

What is the energy source of a star?

• Fusion of gas and dust particles

• Chemical reactions

• Nuclear fission

• Fusion of hydrogen atoms into helium

What determines the life cycle of a star?

• Its location in the galaxy

• Its mass

• Its density

• Its temperature

What happens when a small star like the sun runs out of hydrogen?

• It explodes into a supernova

• It turns into a neutron star

• The core starts to collapse and hydrogen fusion starts in a shell around the core

• It immediately becomes a black hole

What does a red giant star become after fusion has stopped and gravity is no longer strong enough to hold onto its outer layers?

• A black dwarf

• A planetary nebula

• A red dwarf

• A neutron star

What is a white dwarf?

• A massive star that can fuse elements up to iron

• The initial stage of a supernova

• The core of a star like the sun at the end of its life

• A newborn star

What happens to very massive stars at the end of their life?

• They turn directly into black holes

• They shrink into neutron stars without exploding

• They become white dwarfs

• They explode in a supernova

What is left after a supernova explosion?

• A white dwarf

• A neutron star or a black hole

• A black dwarf

• A planetary nebula

How are heavier elements than hydrogen and helium (up to iron) created?

• By collisions between galaxies

• On planets with strong magnetic fields

• In the core of massive stars through fusion

• Through chemical reactions in space

Why is understanding stars crucial according to the text?

• Because they are beautiful to look at

• Because they can potentially support life

• Because they tell us where we came from

• Because they help us predict our individual future.