# Can nuclear fission or fusion occur together with bond formation in a reaction?

Is it possible for a nuclear reaction to occur simultaneously with a chemical reaction involving bond formation?

Can anyone suggest an example of this, please?

• The question is badly worded- there are three general categories of nuclear reactions- fusion, fission and decay/recombination. – user2617804 Oct 7 '14 at 6:39

## 4 Answers

I can't think of any examples of a nuclear reaction leading to a chemical reaction with bond formation. But you got me curious and I started wondering if the reverse process, i.e. chemical bond formation leading to a nuclear reaction might be possible. I couldn't think of any traditional bond formation reactions that would fall into this category. The closest I could come is the following reaction.
$$\ce{^{2}_{1}H + ^{3}_{1}H -> ^{5}_{2}He -> ^{4}_{2}He + ^{1}_{0}n + Energy}$$ Once formed, the $\ce{^5He}$ is consumed by a nuclear decay process - there's half of what we were looking for. When we produce $\ce{^5He}$ from deuterium and trtium atoms, the two electrons that were once orbiting those separate atoms are now both orbiting a common atom - not a traditional chemical bond, but those two electrons are now occupying the same $\ce{1s}$ orbital and obeying the Pauli exclusion principle just as electrons in molecular orbitals do; and their once independent trajectories in space has been dramatically altered to where they are now orbiting a common nucleus.

It has been done, not with bond formation but rather with bond breaking, and is called the Szilard–Chalmers reaction (credit to Loong for pointing out the name).

When a biphasic mixture of ethyl iodide (with stable $\ce{^{127}I}$) and water is irradiated with neutrons, all the radioactivity from $\ce{^{128}I}$ is found as iodide in the aqueous phase; there is none in the organic phase. This is because $\ce{^{128}I}$ is initially formed in an excited state that emits a γ-photon, and the recoil from that is more than enough to break the C–I bond.

The energy of a γ-photon is > 10 keV; in comparison, the strength of a typical chemical bond is ~ 1 to 10 eV. The C–I bond strength is roughly 2.5 eV.

To start with, fusion can be eliminated because of the intense pressure and high temperature needed. Chemicals would not exist since the electrons have been liberated from the nucleus.

When an atom undergoes fission, the release of energy would probably force the other nearby atoms away. Pitchblende is composed mostly of $\ce{UO2}$, and some $\ce{U3O8}$. $\ce{^238U}$ eventually decays to $\ce{^226Ra}$. The oxide formed would be $\ce{RaO}$. I don't know what happens to the freed electrons and oxygen ions, though.

• You are correct about fusion. Fission is also too energetic. – user2617804 Oct 7 '14 at 6:41

This moves into the realm of particle physics rather than chemistry, but if you replace an electron in $\ce{H2}$ with a muon, the bond length shortens appreciably to the point where the hydrogen atoms are brought close enough together where they might fuse at room temperature. This process is known as Muon-catalyzed fusion and it would make hydrogen fusion much easier...if it weren't for the fact that it isn't easy to generate a lot of muons and that they seem to get "stuck" on a particular hydrogen and can't continue to catalyze the process.