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What are stars made

7 Answers
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M

Actually stars have very few elements in them except hydrogen and helium. They generally form in an area such as the Orion Nebula. They form from a molecular cloud consisting mainly of hydrogen with maybe 25% helium in the mix. The size of the star depends on the massiveness of the cloud. The life of the star depends on the size of the star. The larger the star the shorter the life.

Someone is going to say, yeah, well look at all of the rocks in the planets in our solar system. Okay, lets look. Five billion years ago our sun was such a cloud. It probably took 10 million degrees to ignite it and our sun was formed. It probably used 90 to 95% of all of the matter in that cloud. So we have left 4 little rock planets, an asteroid belt and would not be close to making a planet in fact one asteriod is 1/4 the mass of rest of belt itself, maybe a 100 moons that may make a Mars size planet (we will count Pluto in there because our Moon is bigger than Pluto), we have the Kuiper belt and the Oort cloud. The other four planets are gas giants. Jupiter alone is over 100 times larger than earth. It is thought that the core is solid helium.

As the cloud forms it begins to rotate and as it rotates the center becomes denser and denser through gravitational contraction. This period lasts for 10 to 15 million years at which time the central core reaches a temperature high enough to produce nuclear fusion. Then a star is born.

There are two forces continuely working on a star. The nuclear fusion on the inside is trying to blow the star apart while gravity on the outside in trying to crush the star. As long as the star stays in equalibrum the star exists.

Our star (the sun) is slightly larger that 1/2 of a solar mass. It will eventually run out of hydrogen and as such the outer layers will cool greatly and it will expand to form a red giant. Expanding perhaps as far as the orbit of the earth. Eventually it will contract and live out the rest of its life as a white drarf. Perhaps its lifetime will be a trillion years.

Stars in the catagory of 7 to 10 solar masses are the type that end in core collapses. These are the stars that make heavy elements. When these stars near the end of their lives the fusion process changes. The hydrogen to helium ends because the hydrogen at the core where the fusion has been taking place is mostly gone. Now helium fuses into heavier elements and so on up the chain. Elements such as lithium, carbon, nitrogen, oxygen, silicon, are formed by fusion all the way up to iron. The process stop suddenly at iron. Iron takes more energy to fuse than it gives off so no longer can the stars fusion reactions counter the force of gravity of the star. Within less than a second the surface of the star implodes on the core and in doing so provides the heat necessary to cause the fusion of elements in the core of the star to heavy elements. The larger the star the more heavy elements and the farther up the heavy element chain.

That is why there is more gold that uranium. And so on. And that is how we know that our world is the result of a super nova or two.

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C

Hydrogen is the most abundant element in the known universe. When it is concentrated in one very large location in space, the gravity of this mass pulls it together to form a huge dense ball, and its density and gravity becoming greater and greater as more hydrogen is pulled in. Once the ball of hydrogen gains a certain "critical mass", it ignites a thermo-nuclear fusion reaction at the core and the ball becomes a giant hydrogen bomb. The only thing preventing the fusion reaction from expanding into space is the gravity of the ball itself, limiting the size of the explosion, and thus the size of the star.

Once the ball is ignited and becomes a star, other elements are formed, such as helium, and some of the others up to and including iron. A first-generation star does not have the ability to create elements heavier than iron, so gold, lead, platinum, and other heavy elements can only be produced when a very massive star collapses and bursts into a super-nova.

Now you can look at your gold ring with the knowledge that it came from the self-destruction of a huge star, amid the chaos and brilliance of one of the most powerful explosions in the universe.

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T

Stars are actually the same thing as our sun. They consist mostly of the element hydrogen. but they contain lower quantities of heavier elements up to iron. They don't however contain anything heavier than Iron. Anything heavier than this is actually created in the explosion of the star( like the gold or silver you might be wearing - created in the explosion of a dying star) due to fusion(combining of two elements giving off energy) Helium is made from two hydrogen atoms. These then combine and so on and so forth.

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S

A star is a massive, luminous ball of plasma held together by gravity. When stars form they are composed of about 71% hydrogen and 27% helium, with a small fraction of heavier elements. A star begins as a collapsing cloud of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Once the stellar core is sufficiently dense, some of the hydrogen is steadily converted into helium through the process of nuclear fusion.

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A

Stars are composed mainly of hydrogen, with most of the rest of their mass being helium. As they get older, some of the hydrogen is converted into heavier elements, including helium, but most of the star will always be hydrogen.

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A

Stars are made up of Hydrogen gas, Helium gas, and many other elements like Carbon, Iron, and many other metals, in decreasing order of their abundance in an average star. Many metals are present in gaseous state in stars.

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S

Most stars are mostly made out of hydrogen. But the stars fuse hydrogen atoms into helium, and then even more complex atoms are created in stars from fusion.

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