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Energy is released by fusion of elements to heavier elements, i.e. fusion of hydrogen to helium in the sun's core.
I'm not sure what you mean by the 'composition of elements', but the hydrogen that our sun, like billions of other main sequence stars, is fusing right now is the leftover hydrogen from the Big Bang which, in billions of years' time, will eventually run out, and stars will have to fuse heavier elements, going up to iron (which means the universe will, eventually, die).
Bigger stars than the sun do fuse heavier elements, in 'layers', with the heaviest (Fe) in the middle, and the lightest (H) at the surface (look up onion structure star).
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∙ 13y ago
Wiki User
∙ 12y agoMainly through fusion of hydrogen. The cores of stars are hot enough and have a high enough pressure to enable nuclii to fuse, which releases a huge amount of energy. The total mass of the fused nuclii is less than the mass of the individual nuclii before fusion, the difference in mass is converted to energy through E=m x (c squared).
Wiki User
∙ 14y agoBy nuclear fusion - How this is achieved is dependent on the mass of the star.
Proton-Proton Chain
Less massive stars, 0.075 to about 1.5 times the mass of the sun normally fuse hydrogen using the Proton-Proton chain.
It starts with Hydrogen Atoms. Consisting of 1 Proton, 0 Neutrons and 1 electron.
2 atoms of hydrogen initially fuse together to make deutirium (a hydrogen isotope with 1 proton, 1 neutron and 1 electron), a positron, a neutrino and some energy.
11H + 11H = 21D + e+ + Neutrino. + 0.42 MeV.
The positron imediately annihilates with an electron releasing gamma rays and more energy.
e+ + e- = 2GR + 1.02 MeV
The deutirium then combines with another hydrogen atom to produce an isotope of helium (2 Protons , a gamma ray and energy.
21D + 11H = 32He + GR + 5.49MeV
For temperatures below 10 million Kelvin hardly any Helium4 isotope is made.
For temperatures above 10 MK there are 3 possible ways to make the helium4 isotope.
For temperatures of about 10 - 14 MK the P1 branch is method.
32He + 32He = 42He + 2x 11H + 12.86 MeV.
The whole P1 process gives a net energy of 26.7 MeV.
For temperatures of 14 - 23 MK the PII branch is the method. (Also called the lithium method)
32He + 42He = 74Be + GR
74Be + e- = 73Li + Neutrino + 0.861 MeV (90%) or 0.383 MeV (10%)
73Li + 11H = 2x 42He
For temperatures above 23 MK the PIII branch is the method.
32He + 42He = 74Be + GR
74Be + 11H = 85Be + GR
85Be = 84Be + e+ + Neutrino + GR
84Be = 2x 42He
Another less common method is the PIV branch.
32He + 11H + 42He + e+ + Neutrino +18.8 MeV
Carbon Nitrogen Oxygen Cycle (CNO Cycle)
For stars greater in mass than 1.5 solar masses the CNO cycle is the main source.
Again there are 2 main methods for fusion depending on which isotope of carbon there is.
CNO-I Cycle (For Carbon 12)
126C + 11H = 137N + GR + 1.95 MeV
137N = 136C + e+ + Neutrino + 2.22 MeV
136C + 11H = 147N + GR + 7.54 MeV
147N + 11H = 158O + GR + 7.53 MeV
158O = 157N + e+ + Neutrino + 2.75 MeV
157N + 11H = 126C + 42He + 4.96 MeV
CNO-II Cycle
157N + 11H = 168O + GR + 12.13 MeV
168O + 11H = 179F + GR + 0.60 MeV
179F = 178O + e+ + Neutrino GR + 2.76 MeV
178O + 11H = 147N + 42He + 1.19 MeV
147N + 11H = 158O + GR + 7.35 MeV
158O = 157N + e+ + Neutrino + 2.75 MeV
Another Cycle that is only significant in the most massive stars is the OF Cycle.
178O + 11H = 189F + GR + 5.91 MeV
189F = 188O + e+ + Neutrino + 1.656 MeV
188O + 11H = 199F + GR + 7.994 MeV
199F + 11H = 168O + 42He + 8.114 MeV
168O+ 11H = 179F + GR + 0.60 MeV
179F = 178O + e+ + Neutrino GR + 2.76 MeV
Our own Sun uses a combination of these methods.
PI method - 86%
PII Method - 13.8%
PIII Method - 0.11%
the remainder is made up of PIV method and also CNO Cycle.
Wiki User
∙ 11y agoA star begins by using Hydrogen for energy. Throughout its life time, the star creates every element from Hydrogen to Iron. Once a star make Iron it explodes and becomes a Supernova, the most violent action ever to happen in the whole universe.
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∙ 14y agoNuclear fusion releases heat, light, and UV rays.
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∙ 15y agoStars release energy primarily through the electromagnetic spectrum. Lots of radiation.
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∙ 14y agoIt is nuclear fusion that powers up stars.
Wiki User
∙ 12y agoThe process is known as nuclear fusion. The isotope hydrogen-1 is converted to the isotope helium-4; a fairly large amount of energy is freed in the process.
Wiki User
∙ 12y agoIt gets radiated out into space, as electromagnetic waves (for example, visible light, or infrared).
Wiki User
∙ 13y agofusion
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Why is Venus a planet not a star?
Stars are mainly made of hydrogen and helium, and produce energy and light with atomic fusion at the core. Venus is made of rock and doesn't produce light, it just reflects light from the sun. Also, stars are hundreds of times bigger than Venus.
Stars produce energy by fusing hydrogen into what?
The products of hydrogen fusion are helium and energy.
Are neutron stars dead?
Yes, in the sense that they no longer produce energy.
Which stars produce most of their energy by the CNO cycle?
Stars that produce most of their energy by the CNO cycle are predominantly those with a mass about 1.3 times the mass of our Sun or greater.Our Sun, and stars comparable in mass or less, predominantly use the proton-proton cycle.
During nuclear fusion what do stars produce?
In nuclear physics and nuclear chemistry, nuclear fusionis the process by which multiple like-charged atomic nuclei join together to form a heavier nucleus. It is accompanied by the release or absorption of energy.
What energy does the sun and stars produce?
the energy sun and stars produce is fusion.
Why is Venus a planet not a star?
Stars are mainly made of hydrogen and helium, and produce energy and light with atomic fusion at the core. Venus is made of rock and doesn't produce light, it just reflects light from the sun. Also, stars are hundreds of times bigger than Venus.
How do hydrogen bombs and stars both produce nuclear energy?
Stars like our sun and hydrogen bombs produce energy through nuclear fusion.
What is the process occurring in stars to produce energy?
Nuclear fusion
Stars produce energy by fusing hydrogen into what?
The products of hydrogen fusion are helium and energy.
What planet produces lots of energy?
The sun because it's hot and humans turn it into energy
What process provides the heat?
Three processes produce heat. Contraction, in both stars and planets; radioactive decay, in planets, and nuclear fusion, in stars.
Stars produce energy by fusing hydrogen into?
Helium atoms
Are neutron stars dead?
Yes, in the sense that they no longer produce energy.
Which stars produce most of their energy by the CNO cycle?
Stars that produce most of their energy by the CNO cycle are predominantly those with a mass about 1.3 times the mass of our Sun or greater.Our Sun, and stars comparable in mass or less, predominantly use the proton-proton cycle.
Hydrogen bombs and stars both produce energy with nuclear?
Nuclear fusion.
During which stage do stars produce energy from the fusion of hydrogen into helium?
Main Sequence
