The Electron Mendacity

NOTE: THIS ARTICLE TAKES NO RESPONSIBILITY IF YOUR BRAIN EXPLODES DUE TO THE FEELING OF HORROR THAT EVERYTHING YOU THOUGHT YOU KNEW ABOUT CHEMISTRY WAS A LIE.

When girls in the Sixth Form told me that Chemistry A level was 'challenging' my reaction was 'pfft, I can handle it'. What the Sixth Formers forgot to inform me of was that our chemistry teachers lied to us.

If you did Edexcel IGCSE Chemistry (triple science or double science) you have been lied to. In fact if you were taught that electron configuration is as simple as two electrons in the first shell, eight in the second shell, eight in the third shell and that 'we don't really look beyond that 'cause it's not very relavent' you have been lied to. 

That's right. Your chemistry teachers, the people you trusted to set your hands on fire with methane bubbles and who tortured you with titrations, lied to you. The amount of betrayal I felt upon being told this was summarised by a lot of hand waving and shocked cries of 'How?!... Why?!... Was that really necessary?!?' 

So now, my dear friends, I will reveal to you what all of your Chemistry teachers lied about.  

Electrons are, as we all know, arranged in shells with n=1 closest to the nucleus. Each electron shell (except n=1) are divided into sub-shells. Each sub-shell consists of electron orbitals which is a region of space which can hold up to two electrons of opposite spin. Orbitals are the regions of space where electrons have a 95% probability of being found. 

Still with me? Recap: Electron shells made up of sub-shells, made up of electron orbitals, regions of space which can hold up to two electrons. 

There are (as far as I know) four different kinds of sub-shells: 

sub-shell:  number of orbitals in sub-shell:  shape of orbital: maximum number of electrons in shell:  

S                      ONE ORBITAL                                     CIRCULAR                                                                                2

P                     THREE ORBITALS                          EACH ORBITAL IS A FIGURE OF 8                                                   6

D                     FIVE ORBITALS                                 ... TOO COMPLICATED FOR MY TEACHER TO TELL ME                        10

F                     SEVEN ORBITALS                            ... IF SHE WOULDN'T EXPLAIN D WHY WOULD SHE EXPLAIN F?             14

Shapes of electron orbitals in the order of: s, p, d, f

Electron orbitals fill very simply. The lowest energy orbital is filled first and each sub-shell made out of orbitals must be completely filled before moving to the next sub-shell. 

Here's a run down of the order in which the shells fill (this may be overwhelming):

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p... etc. 

When you're writing the electron configuration of an element to show how many electrons are in each sub-shell you put a little number (like an indice number) by the letter. 

e.g. Beryllium, which has four electrons in its shells, has an electron configuration of 1s²2s²

And that's the basics of it! Do you feel the The 'e tu, brute?' moment? The stab of betrayal at the devastating lies we naively believed for so long? (Ok so they weren't really lies, they were more like extreme simplifications... But it's still nice to understand how electrons are actually arranged right?!)

So A level Chemistry. Definitely a leap up from GCSE and definitely making me use my brain but, oh, how satisfying to finally uncover what I have dubbed The Electron Mendacity.

When it comes to Chemistry I do, however, still hold the opinion of 'pfft, I can handle it' ... We'll see how long that lasts.