When I think about splitting of the atom, my thought process generally goes along the lines of “Ahh yes, I have heard of an atom before. They simply split that and created a bomb” and that would be that. However after recently watching a BBC documentary [1] on Sellafield it suddenly dawned on me that there was more to it than I had originally thought, and I was inspired to delve deeper into the atom.
If you are as equally intrigued, please join me on this journey of discovery, where we will find out; what is meant by splitting the atom; how the atom is split; and why the atom being split is important to us today.
There is more to the whole “Splitting the atom” than just creating a bomb, which is perhaps the most famous example. But what exactly is it? Which atom is split, and why is that atom special? As the BBC [2] put quite nicely, “All substances are made of tiny particles called atoms”, which brings more questions than it answers. Splitting the atom hints that there is only one atom which can be split. But if all substances are made up of atoms, then which is the atom? Which is the special one that can be split, or does it not matter? Surprisingly (well for me anyway) no, it doesn’t matter, every element’s atom can be split! However in the terms of what we generally associate splitting the atom with (nuclear power and bombs) then yes it does matter! Now I can imagine you are all sat there thinking I am a bit of a wolly, “How can it not matter, and then in the next sentence it does matter?” More on that later.
First lets look at what splitting the atom is.
I am going to introduce some new terms here. Partly because I have just read and understood about them, and partly because if we are going to talk science we may as well use the correct terms.
- Fission is where an atom is split into two or more smaller atoms [4]
- Fusion is where two or more atoms fuse together to make a bigger atom [4]
Of the two Fusion is the only one that occurs naturally, interestingly in our very star (and every other star).
Clik here to view.
I hope you all recognise the sun, it is quite important to us so should be something you are familiar with. But I digress, back to something a little bit smaller; the atom.
NB: Technically spontaneous fission can occur, but it is extremely rare.
As the title suggest, we are interested in splitting the atom, meaning that we want to look at fission not fusion. If you are interested in fusion (which I sure am) then check out my future blog post (currently the future hasn’t arrived yet, so you will need to wait). But for now, we will delve into how an atom is split.
An atom splitting into two parts occurs when the nucleus is bombarded with other subatomic particles known as neutrons [5] (If you are a little bit confused as to what the heck an atom is, and what it comprises of, check out this future post). When the nucleus and neutron successfully collide, the nucleus splits in (roughly) half, however the resulting pieces have less combined mass then the original nucleus. Now those of you who are paying attention will be asking “Well where did the rest of the mass go?”, which is a very good question. The remaining mass is converted into energy [5]. When done in small amounts, this is a small amount of energy. However when performed in massive quantities, the amount of energy that is created is, you guessed it, MASSIVE.
Can you remember a few paragraphs ago I said that it does matter which atom is split, for the use of nuclear power? Well heavier elements, such as uranium, are “better” (in the sense that they give off more energy) for nuclear fission than lighter elements. Splitting a heavier element produces more energy, which is important for why we bother to split the atom anyway, which I will explain next. Having said that, the principle is the same with every atom, in that energy is given off when the split occurs.
With this knowledge, we can see why splitting the atom has big implications and is important to us. Perhaps the most famous occurrence is the atomic bomb, which was used in 1945. This was the result of large amounts of atoms being split at once, whereby “The energy released by fission is a million times greater than that released in chemical reactions” [4], thus a big explosion that devastated an entire city.
However nuclear fission (splitting the atom) can have multiple benefits; nuclear power stations to generate electricity by boiling water that is heated by nuclear fission [7]; and even to power spacecraft (although this didn’t transpire), to name just a few.
To Summarise; Any atom can be split, however heavier elements produce more energy when they split (which is why uranium is commonly used, as this is a heavy element); Splitting takes place when the atoms are bombarded with neutrons; and humans can harness the energy that is produced by this split.
So there we have it, a brief rundown of splitting the atom, looking at; what it is; how it is achieved; and why we should care. I would love to go into further detail, but there is simply too much to look at, at least for this post. Keep an eye out for future posts, where I am more than likely to delve deeper into specific areas; expanding our knowledge of science and its mind boggling workings (although hopefully less mind boggling now you have read this).
Edit: Sept 29th 2015; Thanks to Jay R, in the comments, for highlighting some errors in my original post.
[1] BBC – Britain’s Nuclear Secrets – Inside Sellafield (2015)
[2] BBC Bitesize – Atoms
[3] BBC Bitesize – Nuclear fission and fusion
[4] Diffen – Nuclear Fission and Fusion
[5] LiveScience – What is Fission?
[6] MadSci Network
[7] BBC Bitesize – Generating Electricity