What type of energy is actually stored inside an atom?

[davLev]

What type of energy is actually stored inside an atom?
When an atom is split—such as in a nuclear explosion—it releases enormous energy, much of it in the form of gamma-ray electromagnetic radiation.
Given this, is it correct to say that the energy stored in the atom is fundamentally electromagnetic (EM) energy?
If not, how should we properly understand the nature of the energy that binds the nucleus and is released during fission?

 

[anuttarasammyak]

Yes. Ref. https://www.feynmanlectures.caltech.edu/II_01.html

 

[davLev]

Thanks.
If the energy stored inside an atom can ultimately appear as electromagnetic (EM) radiation when the atom is broken, does this imply that EM energy is required to form or “set” an atom in the first place?

 

[DaveC426913]

Thanks.
If the energy stored inside an atom can ultimately appear as electromagnetic (EM) radiation when the atom is broken, does this imply that EM energy is required to form or “set” an atom in the first place?

Energy is not a thing in itself; it is a property of a system, and it can change forms. A fast-moving atom has kinetic energy, which, if directed upward can be converted into potential energy, or if toward the ground, can be converted to heat energy, etc.

When an atom is split, the components often have less mass than when they were together, and the slight difference is released in various forms, sometimes as a small massive particle, sometimes as EM which, while massless, does have momentum.

Atoms are usually formed in the process of nucleosynthesis - a term you will want to look up. Sometimes the energy source is kinetic - if you bang two small nuclei together hard enough, sometimes they stick. That is an example of an atomic nucleus that has formed without the injection of EMR.

Ideally, others will come along and tidy up my sloppy explanations.

 

[anuttarasammyak]

EM energy is required to form or “set” an atom in the first place?

The electromagnetic repulsive force is an obstacle that must be overcome to achieve nuclear fusion. This condition is satisfied in the interior of stars.