Consider the case of a single positive charge center and a single negative charge in circular motion at speed c.
mec2rpe=q.q4πεor2pe
In general for a electrically neutral system of 2n charges, n positive and n negative,
mec2rn=n2q24πεor2n
rn=n2q24πεomec2
rn+1=(n+1)2q24πεomec2
obviously rn+1>rn, but the corresponding potential energy term,
PEn=n2q24πεorn=mec2 which is a constant
Suppose a nucleus of n+1 positive charge, emits a positive-negative charge pair, both charges leave the atom, then n negative charges will be caught at a higher orbit. This can be the case of disassociated hydrogen gas where a number of the ionized atoms come together to for a loose nucleus, under high temperature.
The potential energy difference is,
ΔPE=n2q24πεorn−n2q24πεorn+1
=n2q24πεo{1rn−1rn+1}
=n2mec2{1n2−1(n+1)2}
In general, for n1 remaining positive charges from a nucleus originally containing n2 positive charges,
ΔPEn1,n2=n12mec2{1n12−1n22}
obviously n1<n2. The final position of the negative charge has a lower potential than before the charge pair leaves the atom. The speed of the electrons at both positions is c, unchanged. So, the energy difference ΔPE is totally emitted, as with the charge pair. Where did this energy go? How did the energy went?
If similar process happens for other elements of higher atomic numbers, where bare nuclei come together to form loose positive charge centers, than it is expected that n2 be a multiple of n1. ie.
ΔPEn=mec2{1−1n2}
where n2=n.n1 and n=2,3,4...
In this case, ΔPEn seems to have lost its atomic number signature. The last expression assume that the nucleus of the elements are not restricted by their geometry and come together freely. In actual cases, some n are not possible for some elements which gives that element its characteristic spectra lines.