Why energy absorbing after Fe and energy realising before Fe ?

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In summary, the release of energy in nuclear fusion for lighter elements is due to their higher binding energy per nucleon compared to heavier elements. This means that fusing light elements into heavier ones results in a decrease in energy, releasing it in the form of excess energy. On the other hand, heavier elements have lower binding energy per nucleon and thus require energy to fuse, resulting in energy absorption. The weak nuclear force plays a role in this process, as it is responsible for the stability of nuclei and governs beta/positron decay. The balance between nuclear and electromagnetic forces is also a factor in determining the outcome of nuclear fusion and fission reactions.
  • #1
Edi
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Thats about it - why does the nuclear fusion release energy when fusing lighter elements, but absorbs energy for heavier elements?
Something to do with the week nuclear forces low range and after Fe it simply crosses that range? But... every hadron in the nucleon has the week force, with its limited range, ...
Or that the week force doesn't add up (limited range) while EM does? But in that case what does make it all "stick", why does giving more energy make it stick?

.. waiting some answers, so I can get clearer on what questions to ask.
 
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  • #2
Edi said:
Thats about it - why does the nuclear fusion release energy when fusing lighter elements, but absorbs energy for heavier elements?
Something to do with the week nuclear forces low range and after Fe it simply crosses that range? But... every hadron in the nucleon has the week force, with its limited range, ...
Or that the week force doesn't add up (limited range) while EM does? But in that case what does make it all "stick", why does giving more energy make it stick?

.. waiting some answers, so I can get clearer on what questions to ask.
I believe one is referring to binding energy - http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html#c1

Fe and Ni isotopes are among the most tightly bound (stable) nuclei, and there is little between neighboring nuclei.

For the lightest elements have lesser binding energy per nucleon comparted to isotopes near Fe, so fusion light elements to heavier elements releases energy. In contrast the heaviest elements have lesser binding energy per nucleon, and the release energy by fissioning into lighter nuclei, e.g. U-235 (+ n) fissioning to Rb-90 + Cs-143 + 3 n.
 
  • #3
Did you mean that lighter elements have more binding energy? Because you both light and heavy elements can't have lesser.. ;)

.. the nuclear binding energy, that is the week force, right?
Light nuclei after fusing have spare, left-over energy, but heavier doesn't have enough, so it needs to absorb it?
Then, by increasing the kinetic energy of particles gives more energy to the reaction, but how does the kinetic energy transfers to increased week force??
 
  • #4
Edi said:
Did you mean that lighter elements have more binding energy? Because you both light and heavy elements can't have lesser.. ;)
I would recommend calculating the total binding energy and binding energy per nucleon for various nuclei.

.. the nuclear binding energy, that is the week force, right?
Light nuclei after fusing have spare, left-over energy, but heavier doesn't have enough, so it needs to absorb it?
Then, by increasing the kinetic energy of particles gives more energy to the reaction, but how does the kinetic energy transfers to increased week force??
Binding energy is actually the energy required to remove one or more nucleons or groups of nucleons (e.g., alpha particle), or the energy to dissociate a nucleus into its constituent nucleons. The total binding energy would be (A-1)*BE/nucleon, but for most practical applications, one refers to BE/nucleon or the BE/(last nucleon).

The BE for the last nucleon is on the order of MeV, and one can use gamma rays, neutrons or other high energy particles to 'knock out' nucleons or particles from nuclei.

Basically light nuclei like d,t, He-3, Li-6 and others fuse and reconfigure. The excess energy is manifest in the nuclear products. A reaction of p + B11 is more accurately fission, since although p fuses with B11, the excited nucleus fission to form 3 alpha particles.

As for forces, it has to do with a balance of nuclear and EM/Coulomb forces. The weak force governs the beta/positron decay.
http://hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html
 

Related to Why energy absorbing after Fe and energy realising before Fe ?

1. Why does energy absorption occur after Fe?

The element Fe, or iron, is located near the middle of the periodic table and has an atomic number of 26. This means that it has a moderate number of protons and electrons, making it stable and less likely to undergo energetic reactions. Therefore, it requires more energy to be absorbed in order to reach a higher energy state.

2. What causes energy release before Fe?

On the other hand, elements with atomic numbers lower than Fe, such as O, have fewer protons and electrons, making them more reactive and unstable. This makes it easier for them to release energy in the form of heat, light, or other forms of radiation in order to reach a more stable state. This is why energy release occurs before Fe on the periodic table.

3. Is there a specific reason for the placement of Fe on the periodic table?

Yes, the periodic table is organized based on the atomic number and electron configuration of each element. Fe falls in the middle of the transition metals group, which are known for their variable reactivity and ability to form compounds with multiple oxidation states. Its placement reflects its properties and behavior in relation to other elements.

4. Can energy be absorbed and released by Fe?

Yes, energy can both be absorbed and released by Fe. As mentioned earlier, Fe can reach a higher energy state by absorbing energy, and can also release energy as it becomes more stable. This is why Fe is used in various energy-related applications, such as in batteries and as a catalyst in chemical reactions.

5. How does the energy absorbed or released by Fe affect its behavior in reactions?

The amount and type of energy absorbed or released by Fe can greatly impact its behavior in reactions. This can include changes in its reactivity, ability to form compounds, and physical properties. For example, when Fe absorbs heat energy, it can undergo a phase change from solid to liquid. On the other hand, when it releases energy in the form of light, it can cause a chemical reaction to occur with other elements or compounds.

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