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When fusion occurs in a star which atoms fuse and what is the resulting atom?
Wiki User
∙ 10y ago
There are several different types of fusion which can occur in stars at different points in their life cycle depending on their mass and metallicity ("metal" means something different to astronomers than it does to most people).
In general, and tremendously simplified, the most common net result of stellar fusion is that one starts with protons (hydrogen nuclei) and ends with alpha particles (helium-4 nuclei). However, there are also (lots of) other things going on, read on if you're interested in more details.
In our own Sun, the most common type of fusion is called the proton-proton chain reaction. In the most common branch of this process, two hydrogen atoms fuse to form deuterium, which fuses with another hydrogen to form helium-3, and then two helium-3 atoms fuse to form helium-4, releasing two hydrogen atoms in the process.
(Note: everywhere I've said "atoms" above I really mean "nuclei"; at the temperatures and pressures required, atoms don't actually exist as independent entities and it's more of a plasma of nuclei and free electrons).
Also, the last step in the process above is called the PPI branch and happens at temperatures of about ten to fourteen million kelvins. At 14-23 MK, the PPII branch is predominant, and involves a helium-3 nucleus fusing with a helium-4 nucleus to form beryllium-7, which then absorbs an electron to form lithium-7, which fuses with a proton (hydrogen nucleus) to form two helium-4 nuclei.
Above 23 MK, the PPIII branch dominates, which again involves fusion of helium-3 and helium-4 to make beryllium-7, which then fuses with a proton to form boron-8, which undergoes beta decay to beryllium-8, which is unstable and immediately splits into two helium-4 nuclei.
There's another branch which has been predicted but never directly observed (PPIV, the fusion of helium-3 with a proton to directly form helium-4). If this does occur in the Sun, it's only in very small amounts (less than about 0.3 parts per million).
In stars more than about 1.3 times the mass of the Sun (and to some extent in less massive stars, including the Sun itself) there's another process called the CNO cycle which has the same net result (protons are consumed and alpha particles are produced). I'm not going to go into the details, because this answer is already long enough, but if you're interested you could look up "CNO Cycle" on, say, Wikipedia.
Heavier nuclei (up to nickel-56) are built by the alpha process. Three alpha particles (helium-4 nuclei) can fuse to form carbon-12 (technically, two first fuse to form beryllium-8, but beryllium-8 is so unstable that unless it immediately fuses with another alpha particle it will just decay back into two helium-4 nuclei again). After that, the elements are built up by the addition of successive alpha particles:
carbon-12 + alpha -> oxygen-16
oxygen-16 + alpha -> neon-20
neon-20 + alpha -> magnesium-24
magnesium-24 + alpha -> silicon-28
silicon-28 + alpha -> sulfur-32
sulfur-32 + alpha -> argon-36
argon-36 + alpha -> calcium-40
calcium-40 + alpha -> titanium-44
titanium-44 + alpha -> chromium-48
chromium-48 + alpha -> iron-52
iron-52 + alpha -> nickel-56
Each of these requires higher and higher temperatures to sustain, so only the highest-mass stars reach this point. Above this the process falls apart, since zinc-60 would be the next product, but this fusion reaction is endergonic (absorbs energy rather than releasing it) and the core of the star collapses instead.
Heat and pressure from the collapse rebounds in a supernova event, which has plenty of energy floating around and can form all kinds of weird heavy nuclei. Supernova explosions are basically the source of all nuclei heavier than nickel.
Wiki User
∙ 10y ago
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Do stars give off light as a part of a nuclear fusion reaction in which helium atoms are split into hydrogen atoms?
No. In a fusion reaction, a heavier element is made of a lighter pair by "gluing" them together in a fusion reaction. When we split an atom, that's called atom splitting, or sometimes fission, not fusion. They are opposites. Stars give off light, but the primary fuel in their fusion engines is hydrogen, which they convert into helium. As the hydrogen burns out, the star begins making helium into carbon.
What is a fusion?
1.)A fusion basically is what gives your parts such as you body, the Sun, Neon's glow, and to not be blind. Without this thing, we wouldn't be alive. Fusion can protect us from cancer, blindnesss, parilaization, and sickness, 2.)The fusion when two matters combine and become one new object like if there is two atoms and then they combine together, it forms a larger, bigger, stronger, atom.
Fission and fusion of nuclear power plant?
Fission is the splitting of an atom, fusion is the joining of 2 atoms into one. In most fission, neutrons are bomabarded at the nucleus of uranium or plutonium and this causes a ripple effect of more neutons being released from the fuel. The process generates large amounts of heat which is either used for destruction or steam engines. Fusion most often occurs with 2 Hydrogens being fused together to form helium. Deuterium (Hydrogen with a neutron and proton instead of just a proton) and tritium (one proton and two neutrons) are high energy atoms that are used in testing nuclear fusion. Our star (the sun) is based, like most stars, on Hydrogen being fused to generate heat and Helium.
What are similarities between fusion and fission?
Binary fission is the form of asexual reproduction and cell division used by prokaryotic organisms such as bacteria or archaea. Similar Organism splits into smaller parts, occur in single celled organisms.
What is going through fusion inside the sun to make helium?
The fusion process of hydrogen to helium in nature is the one that powers stars. The net result is the fusion of four protons into one alpha particle, with the release of two positrons, two neutrinos (which changes two of the protons into neutrons), and energy, but several individual reactions are involved, depending on the mass of the star. For stars the size of the sun or smaller, the proton-proton chain dominates. Two sets of two separate 1H protons fuse into two sets of a 1H proton and 2H proton-neutron while (both sets) release a neutrino and a positron. The resulting two 1H proton and 2H proton-neutron sets fuse into two atoms of He3 (2 protons and a neutron) while emitting gamma radiation. In the final stage the two He3 atoms fuse into a single He4 (2 protons, 2 neutrons) atom while emitting 2 H1 protons.
What is the differenc between nuclear fusion and nuclear fission?
Fusion means to combine lighter atoms into a heavier atom. Fission means to split a heavy atom into lighter atoms.
In the process of fusion the sun process energy how?
In nuclear fusion, you take 4 atoms of hydrogen, and fuse them into helium. The resulting atom has less mass then the 4 atoms combined. That loss of mass is what we gets as energy. How much energy you may ask? E = mc2.
Where does the sun get its energy from and how does it make or get energy?
The nuclear fusion that converts two hydrogen atoms into one Helium atom produces energy. It occurs at the core of the Sun.
What type of reaction occurs in a nuclear power plant?
It is NOT a chemical reaction, but a FUSION of atoms. Say two atoms of hydrogen may fuse together to form an helium atom , with the consequent release of energy.
What is created when two hydrogen atoms fused together?
Hydrogen atoms have one proton in their nuclei. When two hydrogen atoms fuse together they make one helium atom that contains two protons in its nucleus. This is called nuclear fusion, which powers the stars in the universe.
What is the process of two atoms combine to make one atom?
Fusion
What is a sentence for the word inter fusion?
The inter fusion of two helium atoms creates a hydrogen atom. This is an example using inter fusion.
When two atoms combine to form a larger atom that process is what?
Atomic Fusion
Does fusion have two Hydrogen Atoms Fuse To Make A Helium Atom?
yes
Is fusion a type of reactor?
Fusion is the combining of two atoms to make one, fission is the splitting of an atom to make two.
The mass of an atom aftre it under goes fission or fusion?
the mass of the atom after fusion is less than the mass of the input atoms. The mass of the fragment atoms after fission is less than the mass of the original atom.
What occurs in nuclear fiusion?
There is no such thing as fiusion. There is fusion and there is fission. fission is when the atoms are spilt apart (like in an atom bomb). fusion is when the atoms are put together (like a hydrogen bomb)
