Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [binding-energy]

Please use binding energy in the context of the atomic scale and/or atomic systems. This can be used in nuclear reactions.

95
votes
11answers
14k views

Why do fusion and fission both release energy?

I only have high school physics knowledge, but here is my understanding: Fusion: 2 atoms come together to form a new atom. This process releases the energy keeping them apart, and is very energetic. ...
34
votes
3answers
6k views

Why do nuclei decay so fast and slow?

Why do nuclei like Oganesson (also known as Ununoctium, this is the 118th element on the periodic table) decay in about 5 milliseconds? This is weird that they decay. In comparison, why do elements ...
32
votes
8answers
8k views

Is (rest) mass quantized?

I learned today in class that photons and light are quantized. I also remember that electric charge is quantized as well. I was thinking about these implications, and I was wondering if (rest) mass ...
25
votes
3answers
19k views

Why is the nucleus of an Iron atom so stable?

Lighter nuclei liberate energy when undergoing fusion, heavier nuclei when undergoing fission. What is it about the nucleus of an Iron atom that makes it so stable? Alternatively: Iron has the ...
25
votes
3answers
4k views

Do chemical bonds have mass?

When an exothermic reaction occurs, the energy in the chemical bonds of the reactants is partially transferred to the chemical bonds of the products. The remaining energy is released as heat. For ...
22
votes
5answers
3k views

Why do unstable nuclei form?

Why do unstable nuclei form? Is it that we simply find unstable nuclei in nature and understand what these nuclei do in order to become more stable? I feel like textbooks gloss over this question ...
22
votes
4answers
12k views

How does rest mass become energy?

I know that there's a difference between relativistic and rest mass. Relativistic mass is "acquired" when an object is moving at speeds comparable to the speed of light. Rest mass is the inherent mass ...
19
votes
2answers
5k views

Why is iron the peak of the binding energy curve?

If Nickel-62 and Iron-58 have more binding energy per nucleon than Iron-56 does, then why is iron-56 shown as the peak of the binding energy curve? Also, does adding neutrons always make the atom more ...
16
votes
2answers
10k views

Why is Iron the most stable element? [duplicate]

Iron has the highest binding energy per nucleon in the entirety of the known elements. But why Iron specifically? What makes it have the highest binding energy per nucleon?
16
votes
2answers
2k views

Why do different elements have different number of isotopes?

For example: Carbon-12,Carbon-13 and Carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively. Lithium-6 and Lithium-7 for lithium,etc. My question is that are ...
16
votes
4answers
600 views

Weak contribution to nuclear binding

Does the weak nuclear force play a role (positive or negative) in nuclear binding? Normally you only see discussions about weak decay and flavour changing physics, but is there a contribution to ...
15
votes
5answers
22k views

Conversion of mass to energy in chemical/nuclear reactions

Is mass converted into energy in exothermic chemical/nuclear reactions? My (A Level) knowledge of chemistry suggests that this isn't the case. In a simple burning reaction, e.g. $$\mathrm{C + O_2 \...
15
votes
4answers
2k views

Why are alpha particles such a prominent form of radiation and not other types of nucleon arrangement?

It is said in many textbooks that alpha decay involves emitting alpha particles, which are very stable. Indeed, the binding energy (~28.3 MeV) is higher than for $Z$-neighboring stable isotopes. But ...
15
votes
3answers
13k views

Protons' repulsion within a nucleus

Do the protons inside the nucleus repel each other by the electrostatic force? If they do, why doesn't the repulsion drive the protons apart so that the nuclei get disintegrated?
12
votes
2answers
5k views

Why are the dineutron and diproton unbound?

It is known that there is no diproton and dineutron nuclei. Does this mean that two protons or neutrons are not actually attracted to each other? Even if the attraction was weak, wouldn't it cause ...
10
votes
3answers
16k views

When a nucleus is split, what form of energy is released?

When an nucleus is split, what form of energy is released? All of the websites I have looked at say there is a lot of energy released when an atom is split, but it never says what form of energy it is ...
10
votes
1answer
11k views

What is so special about iron?

I remember reading something about how iron was a highly stable element. Ever since then, I have looked at iron fry pans with new-found respect. However, in a recent discussion I was unable to ...
10
votes
2answers
10k views

How to explain $E=mc^2$ mass defect in fission/fusion?

What is the nature of nuclear energy? This is closely related to the correct explanation of mass defect. I did some research of that topic and cannot come to a single comprehensive and consistent ...
9
votes
3answers
3k views

What is the difference between a neutron and hydrogen?

Differences? They are both an electron and a proton, since the neutron decays to a proton and an electron, what's the difference between a neutron and proton + electron? so is it just a higher binding ...
9
votes
3answers
13k views

Why can't Iron fusion occur in stars?

It is said that iron fusion is endothermic and star can't sustain this kind of fusion (not until it goes supernova). However star is constantly releasing energy from fusion of elements like Hydrogen ...
9
votes
4answers
21k views

Where does the energy from a nuclear bomb come from?

I'll break this down to two related questions: With a fission bomb, Uranium or Plutonium atoms are split by a high energy neutron, thus releasing energy (and more neutrons). Where does the energy ...
9
votes
2answers
3k views

Mass defect- From where mass is being lost?

As a school student, I have wondered while studying mass defect the following mysterious problem My assumption Just like a car's mass is constituted by each part of it(i.e total mass of car will be ...
9
votes
2answers
1k views

Why more Fe-56 than Ni-62 as fusion product in heavy stars?

Suppose we create an Fe-56 nucleus and an Ni-62 nucleus, each from individual protons and neutrons. In the case of Ni-62, more mass per nucleon is converted to binding energy. Thus we could argue the ...
9
votes
1answer
958 views

Obtaining isotope stability

For a given isotope, one can obtain the binding energy using the semi-empirical mass formula. For example, has a binding energy of 1782.8 MeV. From this information, how can the likelihood of the ...
8
votes
3answers
12k views

Why only light nuclei are able to undergo nuclear fusion not heavy nuclei?

Is it because of the binding energy or the binding energy per nuclei . I am having trouble with this whole binding energy and nuclear fusion concept.
8
votes
4answers
7k views

Why are heavier nuclei unstable?

If you have more neutrons than protons, then there will be more strong force present to counteract the repulsive forces between protons. Why is it that above bismuth, no nucleus is stable, regardless ...
8
votes
3answers
3k views

Why are synthetic elements unstable?

So far 20 synthetic elements have been synthesized. All are unstable, decaying with half-lives between years and milliseconds. Why is that?
8
votes
2answers
1k views

What elements can be created in the fusion process of different types of stars?

As I understand it fusion inside a sun can produce heavier and heavier elements until some sort of "nucleus size limit" is reached. As far as I understand, the limit is thought to be reached with the ...
8
votes
3answers
730 views

Are chemical bonds matter?

So it recently blew my mind that chemical bonds have mass. And that a spring that's wound up similarly weights a little more. But there is a distinction between mass and matter. I believe that a ...
8
votes
1answer
754 views

What if the binding energy becomes larger than the rest mass?

Looking at the equation for binding energy and mass defect, $$ B = m_{\text{free}} - m_{\text{bound}} \\ \Rightarrow m_{\text{bound}} = m_{\text{free}} - B, $$ my question is the following. Suppose ...
8
votes
0answers
640 views

What is the theoretical efficiency of fusion?

What is the theoretical limit of the amount of energy that can be extracted from a fusion reaction? I am not talking about the practical efficiency of a reactor, but rather what fraction of the mass-...
6
votes
4answers
3k views

About mass defect

Here's how my book explains mass defect: Particles inside the nucleus interact with each other - they feel attraction. The potential energy $U$ of such attraction is negative, because in absence of ...
6
votes
2answers
3k views

If we assume that protons don't decay, then will all matter ultimately decay into Iron-56 or into nickel-62?

Wikipedia says that all matter should decay into iron-56. But it also says Nickel-62 is the most stable nucleus. So could this mean that in the far future, everything could (through quantum tunneling)...
6
votes
3answers
5k views

Gravitational Potential of a Sphere vs Gravitational Binding Energy of a Sphere

My question is about two equations regarding uniform spheres that I've run into: $\quad V=\frac{GM}{r},$ and $\quad U = \frac{3}{5}\frac{GM^2}{r}.$ 1) On one hand, $V$ is unknown to me, and is ...
6
votes
1answer
470 views

Does the Strong Nuclear Force follow Superposition?

I have just started the study of nuclear physics in my high school, and while reading about nuclear forces and binding energy per nucleon, I found out that the nuclear forces are highly short ranged ...
6
votes
1answer
2k views

Where does energy come from in a nuclear fission if nucleon count doesn't change?

In a nuclear fission the total number of protons and neutrons are conserved. Then the mass converted to energy $E=mc^2$. From where this mass come from? Does that mean that all protons and neutrons ...
5
votes
2answers
212 views

Why does a star die once it has iron?

I found out that iron is the death element for stars, but I couldn't find why can anyone knowledgeable on stars explain why iron causes the star to die?
5
votes
4answers
1k views

Tritium decay is spontaneous even if the binding energy of tritium is higher than the binding energy of 3He. Why?

Given this nuclear reaction: $^3_1\mathrm H\to {}^3_2\mathrm{He}+e^-+\bar{\nu}$ and knowing the binding energies: $BE(^3_1\mathrm H)=8.48 \,\mathrm{MeV}$ $BE(^3_2\mathrm{He})=7.72 \,\mathrm{MeV}$ ...
5
votes
3answers
2k views

What is the binding energy of a neutron star?

Neutrons which constitute a neutron star have a rest mass that is greater when separated from the star because they are bound with a certain potential energy. This potential energy causes the system ...
5
votes
1answer
964 views

Binding energy and mass

I’ve been told that a greater binding energy means the nucleus is more tightly bound, and therefore that decreases the mass of the nucleus with respect to its nucleons when separated. But why does a ...
5
votes
1answer
2k views

Why are there no stable isotopes with an atomic mass of 5 or 8?

One of the things I've encountered in my travels is the mass-5 roadblock. Rod Nave writes about it on his excellent educational hyperphysics website: The helium-4 nucleus or alpha particle with a ...
5
votes
1answer
241 views

What does energy represent in $E= mc^2$?

Due to energy-mass equivalence, any object with mass can be said to have a corresponding amount of energy. So in a 5kg object there are 450,000,000,000 joules. A joule as I understand it is the ...
5
votes
2answers
2k views

Energy conservation in radioactive decay

To show my current understanding, I'll use alpha decay as an example and list my questions at the end. Could you please correct me if I'm wrong. An alpha particle forms in the parent nucleus. It's ...
4
votes
3answers
8k views

Why do only heavy radioactive elements perform fission?

Why do only heavy radioactive elements perform fission? I mean what's so special about heavy elements which makes them ideal for nuclear fission? Also why do only neutrons show fission/fusion and why ...
4
votes
2answers
1k views

Why nuclear fusion deliver energy instead of taking? [duplicate]

In nuclear physics, when you break eg. a nucleus of Uranium, some neutrons are liberated, and the original atom degrades to a lighter element. The energy that was used to keep these subatomic ...
4
votes
3answers
320 views

Does the mass of object really increase?

We were taught the concept of binding energy, We first started with the example of two blocks with some masses having a spring between them. And now they are released from their position, As they ...
4
votes
2answers
300 views

Why is binding energy $\Delta mc^2$?

As we know the mass-energy equivalence relation $E=mc^2$ originally came from special relativity. And the binding energy is $\Delta mc^2$. How do we know that the extra mass coming from theoretical ...
4
votes
4answers
513 views

Does a proton have a binding energy?

When calculating the $Q$-value, $Q = \Delta M \cdot c^2$, of this reaction: $$ ^6Li \ (\alpha, p)\ ^9Be \quad \iff \quad \alpha + \ ^6Li \ \longrightarrow \ ^9Be + p $$ The $Q$-value can also be ...
4
votes
1answer
150 views

Why is energy emitted when nucleons come together?

In terms of nuclear fusion, why exactly does the coming-together of nucleons result in a net gain of energy (at least until iron)?
4
votes
1answer
2k views

Potential Energy in General Relativity

I often hear about how general relativity is very complicated because of all forms of energy are considered, including gravitation's own gravitational binding energy. I have two questions: In general ...