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Stars GapFill
Target Level
C
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1 of 3
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Stars are massive bodies consisting of plasma which fuse light elements and produce energy.
Stars form in nebulae; huge seas of gas and dust which, over time, coalesce via gravitational attraction to create regions of high density. Eventually a region becomes dense enough to be considered ; some of these never reach masses high enough to begin fusion, and will instead form inert gaseous planets, such as Jupiter.
Once a star begins fusing hydrogen into heavier elements, it is considered to be ; this is the phase of stellar evolution which lasts the longest. During this period, gravity and fusion balance each other to create a stable star.
After running out of hydrogen to fuse, a low mass star will become a when it starts to fuse helium, and the outer layers of the star expand. It will eventually lose these outer layers, which form , and the star's core slowly cools as a .
A high mass star will instead become a . These stars eventually explode into , with the core left behind being either a black hole or a , depending on the mass of the core.
The chemical composition of stars can be determined from their , formed when electrons drop down energy levels and release a photon.
Stars form in nebulae; huge seas of gas and dust which, over time, coalesce via gravitational attraction to create regions of high density. Eventually a region becomes dense enough to be considered ; some of these never reach masses high enough to begin fusion, and will instead form inert gaseous planets, such as Jupiter.
Once a star begins fusing hydrogen into heavier elements, it is considered to be ; this is the phase of stellar evolution which lasts the longest. During this period, gravity and fusion balance each other to create a stable star.
After running out of hydrogen to fuse, a low mass star will become a when it starts to fuse helium, and the outer layers of the star expand. It will eventually lose these outer layers, which form , and the star's core slowly cools as a .
A high mass star will instead become a . These stars eventually explode into , with the core left behind being either a black hole or a , depending on the mass of the core.
The chemical composition of stars can be determined from their , formed when electrons drop down energy levels and release a photon.