The Life Cycle of Stars 0.0 / 5 ? PhysicsThe Life Cycle of StarsGCSEAQA Created by: kennedylilyCreated on: 29-12-15 10:23 What is the first stage of the life cycle of a star? A nebula 1 of 22 What is the second stage of the life cycle of a star? A protostar 2 of 22 What are protostars made of? Dust and gas 3 of 22 How are protostars formed? They are formed when the force of gravity makes the dust and gas spiral in together to form a protostar 4 of 22 What happens to cause the temperature to rise in a protostar? Gravitational energy is converted into heat energy 5 of 22 What happens when the temperature gets high enough in a protostar? Hydrogen nuclei undergo nuclear fusion to form helium nuclei and give out massive amounts of heat and light; a star is born! 6 of 22 What is the third stage of the life cycle of a star? A main sequence star 7 of 22 What happens to create a main sequence star? The heat created by the nuclear fusion provides an outward pressure to balance the force of gravity 8 of 22 How long does a main sequence star remain stable? Several billion years 9 of 22 How does the star maintain its energy output for millions of years? There are massive amounts of hydrogen that it consumes 10 of 22 What is the heaviest element made by nuclear fusion? Iron 11 of 22 What happens to a small/medium-sized star when the helium runs out? The star swells into a red giant 12 of 22 Why do the stars become red? This is because the surface cools, so it is no longer white 13 of 22 What does red giant become when it becomes unstable and how? It ejects its outer layer of dust and gas and becomes a planetary nebula 14 of 22 What is the stage after a planetary nebula? A hot, dense solid core is left - this is a white dwarf 15 of 22 What is the final stage after a white dwarf? The white dwarf cools and becomes a black dwarf, which eventually disappears 16 of 22 What happens to a large-sized star when the helium runs out? The star swells into a red super giant 17 of 22 Why do big stars begin to glow brightly again? They undergo more fusion, and expand and contract several times, forming elements as heavy as iron in various nuclear reactions 18 of 22 What is the next stage after a super red giant? Eventually, the red super giant explodes in a supernova 19 of 22 What is formed during a supernova? Elements heavier than iron are formed, and they are ejected into the universe to form new planets and stars 20 of 22 What is the first thing that can be produced after a supernova and how? The exploding supernova throws the outer layers of dust and gas into space, leaving a very dense core called a neutron star 21 of 22 If the star is big enough, what is produced after a supernova? A black hole 22 of 22
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