I understand that an atomic bomb works by detonating fuel (uranium or plutonium) that sparks a chain reaction of fission so every atom causes the fission of more atoms until the fuel is used up. But I don’t understand 2 parts of this process:
1. Why does the fuel (uranium atoms) blow up? I see some sources saying the atoms are being split, but other sources say atoms are being smashed into each other. Which is it? And why does performing that action cause an atom to violently explode?
2. Once the fission is happening and growing exponentially through the fuel, why doesn’t it set off a chain reaction with the atmosphere? Why exactly can’t uranium spark the fission of nitrogen? Why does the chain reaction stop when the uranium is gone?
I know other atomic bomb questions have been asked, but in my research I couldn’t find these answers. Thanks so much!
In: Chemistry
1. When nuclear fission splits in the case of Uranium-235 or Plutonium-239, energy is released – quite a lot of energy given their mass. A neutron collision usually causes fission, but a U-235 splitting will create 3 additional neutrons to split up other nearby uranium atoms.
2. Eventually, you run out of uranium atoms to split, so the reaction terminates. That chain reaction of neutrons smashing into an cleaving uranium ends as there is no more uranium. This isn’t the mechanism through which atmospheric atoms would split. I think the Manhattan Project did have concerns about the atmosphere igniting though. But that’s not through a nuclear reaction, just a general chemical reaction.
Interestingly, in nuclear power plants, they will use control rods to collect those neutrons to prevent an uncontrolled chain reaction.
Man, I learned this stuff in Grade 4 with Microsoft Encarta. Good memories.
Latest Answers