15 votes
Accepted

Does antimatter have the same half-life as ordinary matter?

To say that scientists have created anti-helium-4 is a bit of an overstatement. Anti helium 4 nuclei (just the nucleus, no positrons orbiting it to make a neutral anti-atom) have been observed in LHC ...
AXensen's user avatar
  • 7,147
14 votes

Cobalt atomic mass less than 100 % isotope mass?

The mass of an atom is actually a little bit smaller than the sum of the masses of its constituents (protons, neutrons, electrons). The missing difference is due to the negative binding energy of the ...
Thomas Fritsch's user avatar
12 votes

Is there proof for: "Elements heavier than iron will decay to iron by processes such as fission and alpha emission"?

Nuclear decay is a quantum process and as long as their exists a final state with lower energy than the initial state, and electric charge, baryon and lepton number are conserved, a nucleus will ...
David Bailey's user avatar
  • 10.9k
6 votes

Is there proof for: "Elements heavier than iron will decay to iron by processes such as fission and alpha emission"?

Just because iron has the lowest mass per nucleon does not imply that everything heavier than iron can decay to it. It is possible that an isotope has less binding energy per nucleon than iron, but ...
AXensen's user avatar
  • 7,147
3 votes

Why doesn't the water in a Light Water Reactor split to $\rm H_2$ and $\rm O_2$?

This is a very interesting question for which I had to do some research. Here is what I found in this article: The water in Light Water Reactors does not split into hydrogen ($H_{2}$) and oxygen ($O_{...
cconsta1's user avatar
  • 277
3 votes

How was Rutherford's model of an atom wrong?

Electron according to classical physics would have centripetal acceleration. All accelerating charges emit EM waves and loose kinetic energy in classical electromagnetism. Therefore electron would ...
Agnius Vasiliauskas's user avatar
2 votes

How was Rutherford's model of an atom wrong?

I think the OP doesnt understand why the electron undergoes acceleration.Well it does because its speed may not change , but its velocity changes.Any object in a orbits is accelerating since velocity ...
Root Groves's user avatar
2 votes

Derivation of mean life of a radioactive nucleus

The basic assumption is that the rate of decay is proportional to the number of unstable nuclei, ie $\dfrac{dN}{dt}\propto N \Rightarrow \dfrac{dN}{dt}= -\lambda N\Rightarrow N = N_0e^{-\lambda t}$ ...
Farcher's user avatar
  • 94.9k
2 votes

Derivation of mean life of a radioactive nucleus

Average values are calculated by integrating over a probability distribution: $$\langle x\rangle=\int_a^b xP(x)\;dx.$$ Thus to solve the problem one must find the probability that a given nuclei does ...
Albertus Magnus's user avatar
1 vote

Is there an equation that can predict black hole formation from neutron star formation from supernova occurrence?

There is no simple equation and different researchers do not agree in detail about which massive stars end their lives as neutron stars and which end up as black holes. Any simple mass criterion is ...
ProfRob's user avatar
  • 129k

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