I want to know what a nuclear bomb truly does – Rafael, age 11, Melbourne
A nuclear bomb, like several bomb, makes an explosion by releasing an infinite quantity of power directly. Nuclear bombs simply use a distinct course of from different bombs.
You might have heard of atoms. These are the super-tiny particles that make up matter – which in flip makes every little thing round us (and us).
Nuclear bombs work by altering the cores of atoms to show them into different sorts of atoms. This course of releases numerous warmth power, which shortly will get transformed into a giant wave of stress: an explosion!
What are nuclei?
Nuclear bombs launch way more power than regular bombs that use chemical compounds akin to TNT. It is because the cores of atoms are held collectively very strongly. However earlier than I get into that, let me clarify a number of the fundamentals.
Atoms themselves are made up of even smaller particles known as protons, neutrons and electrons. A cloud of electrons surrounds a tiny interior core product of protons and neutrons. This core is known as the nucleus, and multiple nucleus are known as nuclei.
AG Caesar/Wikimedia Commons
Chemical reactions occur when electrons are rearranged, whereas nuclear reactions occur when protons and neutrons contained in the nucleus are rearranged.
There are two sorts of nuclear bombs. Within the case of “fission” bombs, nuclei which have numerous protons and neutrons – akin to these in a really dense steel known as uranium – are cut up aside.
In one other sort of nuclear bomb known as a “fusion” bomb, two very small nuclei – such because the cores of two hydrogen atoms – are caught collectively.
However fission bombs are less complicated and extra frequent, so let’s discuss these.
Some nuclei don’t take very a lot power in any respect to separate aside, akin to these in some sorts of uranium or plutonium atoms (plutonium is one other dense steel which has 94 protons in its nuclei).
These nuclei will generally fission even after they’re simply sitting round. When a nucleus fissions, it turns into two smaller nuclei and spits out a number of neutrons.
Nevertheless, one nucleus doing this isn’t a giant deal. To make an explosion, you might want to have a certain quantity of uranium collectively in a single spot.
As an illustration, a fission bomb would often use a really purified sphere of uranium weighing about 52kg. Even this must use sure sorts of uranium during which the atoms have a particular variety of neutrons.
When you’ve got sufficient of those atoms collectively in a single spot, the neutrons which are spit out throughout fission will hit different nuclei, which then additionally fission and spit out extra neutrons – and so it continues in a sequence response that units off a large explosion.
Tailored from MikeRun/Wikimedia Commons
An unexploded fission bomb will often be holding separate items of uranium (or plutonium) which are too small to begin the chain response on their very own. A chemical explosive is used to smash the items collectively – triggering the chain response that units the bomb off.
Tailored from Fastfission/Wikimedia Commons
After fission occurs, the 2 smaller nuclei which are left over are radioactive. Having sufficient of them in a single spot will be very dangerous to human well being.
These leftovers after a nuclear explosion are known as “fallout”. Apart from the large measurement of the explosion itself, the fallout particularly is what makes nuclear bombs extra harmful than different bombs. The expertise used to make nuclear weapons is a number of the most secret info on the planet.
Nuclear bombs have solely ever been used twice. Each of those bombs had been detonated throughout World Conflict II, by the USA towards Japan. Folks around the globe are working arduous to ensure they’re by no means used once more.
Kaitlin Cook dinner receives funding from the Australian Analysis Council.