system
Given the following post, respond as if you're commenting on Reddit:
human
In laymen's terms, why does splitting an atom release so much energy?
gpt
Most interactions we see in our daily lives are due to electrons - electricity and chemical reactions.  Electrons are really small, light particles, and the forces keeping them in the atom is only strong enough to keep them in a (compared to nuclear scale) quite large cloud around the nucleus.

Nuclei are made of protons and neutrons, which are approx. 2000 times heavier.  The forces keeping them in place are necessarily much stronger, and therefore have more energy associated with them.  

But it doesn't necessarily follow from the above that splitting an atom should release energy.  If the forces were simple attraction, it would be hard to split an atom, and there would never be any energy given off.  But the forces involved are more complex, and only relevant at very short ranges, more like glue than an attractive force.  When you break the glue, the resulting particles repel each other strongly, and move apart with a lot of kinetic energy.  Electromagnetic energy may also be released directly as gamma rays.

Of course, splitting one atom doesn't release monstrous amounts of energy - the reason an atom bomb works is because of the domino effect, a cascade of atom-splitting that multiplies and multiplies until the available fuel is used up.  Imagine a tree structure where starting one domino at the top sets off 2 lines, then 4, then 8, then ..... then 2,000,000,000 dominos simultaneously.  You may think it's a huge jump from 8 to 2,000,000,000, but it's not as big as you think.