Energy needed to split an atom

[eddybob123]

Is there a table or a graph out there that states the amount of energy needed to split an atom? I know about ionization energies and all that, but there wasn't anything on the internet on how much energy is required to ionize the whole atom. Thank you in advance

 

[Drakkith]

What do you mean by split? Simply causing part of the nucleus to be ejected, such as a neutron or an alpha particle? Or something similar to nuclear fission in Uranium where the nucleus splits into to large pieces and emits several neutrons at the same time?

 

[eddybob123]

I mean both taking the electrons away from a nucleus and then splitting that nucleus, if you know what I mean. For example, seperating the proton and the electron from a hydrogen atom, or ionizing the two electrons from a helium atom then splitting the two protons and neutrons.

 

[Astronuc]

I mean both taking the electrons away from a nucleus and then splitting that nucleus, if you know what I mean. For example, seperating the proton and the electron from a hydrogen atom, or ionizing the two electrons from a helium atom then splitting the two protons and neutrons.

For a rough estimate, simply take the atomic masses for the two nuclei to be produced, and subtract the atomic mass of the original nucleus, and multiply by c².

See - mass.mas03 - Atomic mass table
http://www.nndc.bnl.gov/masses/index.html

 

[Drakkith]

Ok, I wasn't sure if you wanted to simply split a certain atom "in half" or actually disassemble it into its constituent parts.
As Astronuc said, if you find the mass of what you want to split the atom into, and then subtract the atom's mass from that, you can find the minimum needed energy.
(IE you can find the mass of 2 protons, 2 neutrons, and 2 electrons and add them all up and subtract the mass of the Helium atom from it to find the energy)

 

[Astronuc]

If one wants to dissociate an atom into its constituent nucleons, then one would apply the energy equivalent to binding energy per nucleon (BE/A) multiplied by the total number of nucleons.

http://www.nndc.bnl.gov/chart/ and click on the box BE/A and select 1 under Zoom.


Perhaps the best way to fission a non-fissile atom is to hit it with an antiproton, but that will anihilate one of the protons, but it releases a lot of energy. It is more practical to hit the nucleus with high energy proton.

 

[eddybob123]

I'm kind of thinking it as the amount of heat energy to split the atom. I'm just a beginner in this field, so I'm not really sure if it is possible to do it with only heat.

This is similar to the ionization energies that I mentioned, except instead of just taking one or two electrons with heat energy, you're taking all of the electrons. Also, I'm not sure if it's possible to split a nucleus with heat energy. If it's not, please tell me.

 

[Drakkith]

I'm kind of thinking it as the amount of heat energy to split the atom. I'm just a beginner in this field, so I'm not really sure if it is possible to do it with only heat.

This is similar to the ionization energies that I mentioned, except instead of just taking one or two electrons with heat energy, you're taking all of the electrons. Also, I'm not sure if it's possible to split a nucleus with heat energy. If it's not, please tell me.

Heat energy is simply the motion of trillions and trillions of particles in an object. When a proton is "heated" to 10 million degrees, all that means is that it is traveling with an enormous velocity.

 

[eddybob123]

So then calculate it with respect to that. If one mole of atoms requires 300 kilojoules to ionize the first electron, then calculate the velocity of the atom.

 

[Drakkith]

So then calculate it with respect to that. If one mole of atoms requires 300 kilojoules to ionize the first electron, then calculate the velocity of the atom.

I'm not sure what you're asking here. Are you wanting something or are you asking someone to calculate something or what?

 

[eddybob123]

I'm just asking for a table, indicating energy needed to split an atom.

 

[Drakkith]

How about the chart here? http://en.wikipedia.org/wiki/Nuclear_binding_energy

 

[daveb]

You also have to be a little more clear on what youmean by "split". Only some atoms are fissionable, but all atoms (AFAIK) can undergo spallation.

 

[Astronuc]

I'm kind of thinking it as the amount of heat energy to split the atom. I'm just a beginner in this field, so I'm not really sure if it is possible to do it with only heat.

This is similar to the ionization energies that I mentioned, except instead of just taking one or two electrons with heat energy, you're taking all of the electrons. Also, I'm not sure if it's possible to split a nucleus with heat energy. If it's not, please tell me.

I think one needs to be clear about terminology. Splitting an atom usually means fissioning the nucleus into two nuclei of lesser Z. Spallation usually usually means knocking out a smaller nuclei leaving a much heavier nuclei, although for light atoms, there is not much different between Zs. Spallation could mean knocking out a proton, deuteron, or alpha particle from a light atom, e.g., C, N, O, B, Al, etc.

Ionization means removing the electrons from an atom, and that does not mean splitting an atom. One may remove one electron up to Z electrons, in which case a nucleus if fully ionized. Electron energies are in the ev up to keV range. In contrast, removing nucleons or nuclear particles from nuclei requires energies in the MeV range.