0
How is a star able to begin helium fusion after it ran out of hydrogen?
Wiki User
∙ 7y ago
The basic idea is that once a star runs out of hydrogen fuel, it starts contracting until it gets hot enough to fuse helium into heavier elements. This happens at temperatures that are quite a bit higher than the temperatures required to fuse hydrogen into helium.
Wiki User
∙ 7y ago
Add your answer:
Earn +20 pts
What is the process that occurs in the Sun's core to produce so much energy?
Answer 1 The process that occurs in the Sun's core to produce so much energy is called nuclear fusion. Inside the Sun the temperature and pressure gets so high that substances fuse to from new substances. This process produces a large amount of heat, light and energy. Answer 2 Fusion. Isotopes of hydrogen bond together to form helium nuclei. Helium is a bit lighter than the hydrogen isotopes from which it is formed, and this difference, known as the mass defect, is matter converted into energy.
Why does a super red giant so bright but has low temperature?
The reason is due to the different production mechanism for the energy output from the star and the increased size of the Red Giant. As a star moves into its Red Giant phase, after not being able to maintain gravitational equilibrium due to hydrogen begin exhausted in the core, the star begins to collapse. This collapse heats a hydrogen shell just outside the core (previously not available for fusion) initiating fusion of hydrogen to helium in the shell. This means fusion is taking place closer to the surface of the star and leads to increased reaction rates then before. This produces enough energy to increase the star's luminosity by a factor of 1,000--10,000. The temperature of the star goes down because the star balloons out with this increased reaction rate, meaning the energy is distributed over a larger area. Hence, you get a bright, cooler star.
Describe the life cycle of a star like the sun?
The lowest mass stars are the red dwarfs, which have a mass of less that half that of our own sun, down to a mass of only 7.5% of our suns mass. So our sun is between 2 - 13 times more massive. Red dwarf temperatures and brightnesses are a lot lower, but they burn fuel much more slowly so have much longer lifetimes.
Is Jupiter's atmosphere breathable?
No. There is no breathable air.No. People would not be able to live breathing Uranus' atmosphere, which is thin and consists mostly of hydrogen (which isn't bad for us), helium, ammonia, and methane (all three of which are not at all good for Earthlings in such high concentration).
What is the cause of sun's enormous energy output?
The fusion of hydrogen into helium, and the conversion of a tiny amount of mass into energy, in accordance with Einstein's equation "E= mc2". The total mass of four hydrogen atoms is SLIGHTLY higher than the mass of one helium atom. This takes place at temperatures in the millions of degrees and under incredible pressure, conditions that are only found in the cores of stars. Here on Earth, we are capable of creating these conditions, but only for tiny fractions of a second. We call it a "nuclear explosion". We _THINK_ we're getting close to creating these conditions in a more controlled manner, in reactors that may eventually be "nuclear fusion reactors", but we're probably 20 years away from being able to do that. Alas, scientists have been saying for 40 years that they were "20 years away" from developing nuclear fusion as a controlled power source. Good thing we scientists are perennial optimists!
How is a sun like star able to being helium fusion?
Hydrogen stalks run out
What is the process that occurs in the Sun's core to produce so much energy?
Answer 1 The process that occurs in the Sun's core to produce so much energy is called nuclear fusion. Inside the Sun the temperature and pressure gets so high that substances fuse to from new substances. This process produces a large amount of heat, light and energy. Answer 2 Fusion. Isotopes of hydrogen bond together to form helium nuclei. Helium is a bit lighter than the hydrogen isotopes from which it is formed, and this difference, known as the mass defect, is matter converted into energy.
Why does nuclear fusion work inside the sun but not in jupiter?
Jupiter is not massive enough to create the high temperature and high pressure required by even deuterium-tritium thermonuclear fusion, the lowest temperature and pressure type of fusion. The Sun is much more massive and can fuse ordinary hydrogen, deuterium, tritium, and helium 3; producing helium. When the sun begins to run out of hydrogen in 6 billion years, the core will collapse and eventually be able to fuse helium into carbon and become a red giant. The red giant will swallow Mercury, Venus and Earth before it stops expanding.
Explain how the sun produse its energy?
The Sun is massive enough to compress hydrogen to a good density, and thick enough to retain heat for a good bit of time, so it is able to fuse hydrogen nucleii together to eventually form helium. This is where most of its heat / light comes from, gases heated by hydrogen fusion.
Does gravity make the sun's heat and light?
Yes. The sun is often cited as an example of energy from fusion of hydrogen atoms into helium. You might consider then that this is "simple" physical chemical reaction between these atoms. However hydrogen does not combine to make helium under normal conditions. What it takes is that the hydrogen atoms are squeezed together by the massive gravity of the sun until the nucleus of each atoms essentially touch and unite to form hydrogen and release energy in the process. In short the Sun is able to convert energy from gravity into light.
How does helium and hydrogen produce so much energy on the sun?
The cores of stars, such as our sun, have high enough temperatures and pressures to enable fusion of hydrogen nuclei - it is very difficult to fuse these positively charged particle together without these conditions. The mass of the nuclei before fusion is greater than the final mass of the fused particles - some of the mass is converted directly into energy through Einsteins equation E=mc2. m represents the mass, which although very small, is multiplied by the speed of light squared (c2), which is a very large number.
Which balanced equation represents a fusion reaction?
Deuterium (D) is a hydrogen isotope with one proton and one neutron. Tritium (T) is another hydrogen isotope with one proton and two neutrons. So when they combine, the result is D + T = He (Helium), which has two protons and two neutrons, + a free neutron. I can write this as D + T = He + n . Unfortunately WA does not have the tools to be able to write this in the usual physicists notation.
What gases are the gas giant planets made mostly of?
Jupiter, the first gas giant from the sun. It's clouds are made out of simple gases like hydrogen,helium,carbon dioxide,water and methane,along with clouds of ammonia ice and ammonium hydrosulphide. There are winds up to 600km per hour,travelling in opposite directions which create the distinct bands. Saturn is composed entirely of hydrogen. The top layer is made up of ammonia crystals and below are ammonium hydrosulphide or water. Beneath the layer of cloud,the pressure is so intense that gas is compressed into a liquid. Uranus's atmoshere is mostly hydrogen and helium, with small quantities of methane. This allows the planet to be able to absorb the Sun's rays, giving the planets distinct blue colour. Neptune has no solid surface to land on. It may have a tiny core of rock.Neptune's atmosphere is mostly hydrogen and helium with traces of methane.
Why does a super red giant so bright but has low temperature?
The reason is due to the different production mechanism for the energy output from the star and the increased size of the Red Giant. As a star moves into its Red Giant phase, after not being able to maintain gravitational equilibrium due to hydrogen begin exhausted in the core, the star begins to collapse. This collapse heats a hydrogen shell just outside the core (previously not available for fusion) initiating fusion of hydrogen to helium in the shell. This means fusion is taking place closer to the surface of the star and leads to increased reaction rates then before. This produces enough energy to increase the star's luminosity by a factor of 1,000--10,000. The temperature of the star goes down because the star balloons out with this increased reaction rate, meaning the energy is distributed over a larger area. Hence, you get a bright, cooler star.
How does hydrogen and helium produce energy?
This question relates to nuclear fusion. Nuclear fusion (which should not be confused with nuclear fission) is a process in which atoms are combined to produce a new atom. This is a very different thing from a simple chemical reaction, and has a lot more energy involved. For example, two hydrogen atoms can be combined to produce a helium atom, and when this happens, a very great amount of heat is released. Helium atoms can also be fused. In fact, every atom we have either is hydrogen, or was built by processes involving fusion at some point, in stars of long ago. Part of the problem with this is that it takes a lot of heat and pressure to make hydrogen atoms fuse into helium. It is easy for a star, which has a lot of pressure and heat inside. But on Earth, doing it the same way would take more pressure than any physical container can hold at a temperature that would vaporize anything we can make things out of. And to make things even more difficult, we have to be able to put fuel in, and have to get more energy out than it takes to run the operation, which is difficult in this case. But scientists are working on it. People are trying to build containment out of magnetic fields. There are other types of attempts also.
What is our evidence that fusion is occurring?
The sun keeps shining and throwing out masses of heat, and calculations show that the fusion of hydrogen to form helium would enable it, and other stars, to keep going for billions of years. Of course we can't get there to examine it closely, but I think the evidence is mainly based on not being able to account for it any other way. Try the question in 'Sun and Stars' category to see if an astronomer can give you a better answer.
What gases do stars have?
The two main gases found is stars are the mainly hydrogen and helium.
