Why does splitting an atom create energy? And why is it so much energy?
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What “stored” the energy there for us to later “release”? The creation of the universe?
When you pop a balloon some energy is released.
When you pop an atom a bit more energy is released.
Usually energy is just that – either heat or electrical voltage or something else. But when an atom is split a tiny amount of mass is converted into energy. Einstein’s E = m*c^2 tells us that mass is worth A LOT of energy and that’s exactly why splitting atoms creates so much energy
So there are two forces acting on those protons in the nucleus. There is an electrical force, and since protons and protons have the same charge, this repels them. There’s also a nuclear force which binds them together in the nucleus of an atom. The nuclear force acts over very short distances, so if you put in a bunch of energy, you can push those protons apart, and eventually the distance is long enough that the electrical force wins, and the protons to flying apart.
For small a small atom like helium, there’s only two protons, so the amount of energy of them flying apart is less than the energy it took to separate them. So if you split a helium atom, you would lose energy. For a bit atom like uranium, there are dozens of protons. Once you get them far enough apart, the electrical force takes over and you get more energy than you put in. So if you split a uranium atom, you gain energy.
the answer is to do with einstein’s famous E=MC² equation. Energy = mass multiplied by the speed of light squared. The speed of light is a big number, so if you square it you get a damned big number.
When you split an atom into two smaller different atoms, the results weigh less than the original. the weight(mass) lost is converted into energy. Stunning loads of energy!
It takes a lot of energy to bind subatomic particles together to form an atom. When an atom becomes unstable, it can “split” into two smaller atoms. The subatomic particles separate to form two smaller atoms, but there’s some of that binding energy left over. That’s what gets released, and it’s very strong. Do this millions of times and ka-boom.
Particles which makes an atom have small range strong force that binds them together, and longer range weaker repelling force. So, this makes two ways to make energy of atom: 1).You either take an atom big to the point of small range force not spreading enough, you bombard it with neutrons and it splits, releasing more high velocity neutrons and recombining into more stable smaller atom, this leads to chain reaction with stable heat output or explosion(nuclear reactors and fission nuclear bombs). 2). You take small atoms containing extra neutron, heat them to the point of them crashing into each other so violently, that they break through the weak long range repelling force and get glued together by strong low range force. This creates tremendous (even compared to fore mentioned fission reaction) amount of energy, but the tricky part is getting to that temperature. It is achieved through separate fission reaction in thermonuclear bombs(like in tsar-bomb), high gravity fields(like inside stars), and fusion reactors for stable output are still being theoritised. Hopefully we can harness thermonuclear energy in safe way before the turn of the next century.
But if you are just curious, where that energy comes from, then the answer is mass. Standalone parts of atoms weight more than combined atom. Not by much, but since E=mc2, even miniscule amount of mass holds incredible amounts of energy.
Einstein realised that matter and energy are the same thing. A little bit of matter is the same as a lot of energy. When you split an atom, the two parts it splits into are slightly less than the whole you started with. The difference is released as a lot of energy.
when an atom splits, it blows off its electrons. so the two resulting atoms have a high positive charge and kind of act like a magnet. they will collect electrons from all around causing friction. and friction = heat and heat = energy
Atoms are made up of Protons, Neutrons and electrons. We can individually ‘weigh’ protons and neutrons to work out their mass (electrons are very low mass, so lets ignore them)
if you jam a bunch of protons and neutrons together to form an atom (lets say uranium 235, that has 92 protons and 143 neutrons, so a big heavy atom)
What should the atom weigh? 92 x proton weight + 143 x neutron weight right? its what you would expect, but it doesn’t, it weights less than this.
This mass difference is made up of the ‘nuclear binding energy’ (yeh, mass converting to energy and back, there is complicated science here too)
So now we crack that atom like a walnut, into two smaller atoms. Now weigh these, surely the total mass will be same the same as the original right? you would think, but the total mass is now a little Higher.
This is now where E=MC squared comes in (its actually change in energy = change in mass times the square of the speed of light) and because of the change in mass, there is a change of energy, and the excess energy gets released as heat/motion, usually through the reaction kicking out a seriously fast moving neutron or similar.
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