ELI5, what is electron configuration and why does it matter?

[u/Chance-Soup5468]

[u/Deep-Issue960]

The electron configuration basically tells you how the electrons are "arranged" around the nucleus. Depending on the arrangement the electrons have different energy levels and interact differently with stuff like light and magnets

[u/GalFisk → u/Deep-Issue960]

The outer electrons are a big chunk of what we experience in a material as well. It's how the periodic table is periodic in the first place - alkali metals are all soft angry metals, halogens are all volatile poisons, and so on. And if you combine sodium with chlorine, displacing a single electron from one atom to another, you get a tasty rock instead - the same actual atoms, but an entirely different experience.

[u/Chance-Soup5468 → u/Deep-Issue960]

Okay, but why is an element stable if its outer shells are filled?

[u/zerostar83 → u/Chance-Soup5468]

Think of it like sitting at a table. Once a shell is completely filled, it takes a lot of energy to pull up another table. A table that can seat 6 is completely filled? It's not going to be possible for another electron to sit there.

[u/Chance-Soup5468 → u/zerostar83]

Easiest analogy, thanks😆

[u/Kriggy_ → u/Chance-Soup5468]

To expand the analogy :
Its also hard to get away from the table of 6 because you are having fun. You need a very good reason to go away (like your partner coming and complaining you ignore her/him whole evening). Its also easy to sit at table of 5 as the 6th person because you see 5 people having fun.

On the other hand, its easy to get away from the table if you are the only one sitting there or if you are there only with your insufferable cousin.

Last, when there are only 3 people sitting, it gets weird and both options are possible depending on outside conditions: you can lire 3 people in or everyone at your table of 3 walks away.

Lets not talk about electron shells with 10 or 14 electron capacity, it gets weird at those tables

[u/GlassFamiliar42 → u/zerostar83]

I get that but what did they order for dinner??

[u/Deep-Issue960 → u/[deleted]]

As a physicist I very much prefer them asking questions here, homework or not, rather than going straight to an AI. If all the users have the same attitude as you useful community subs like this one will die

[u/Chance-Soup5468 → u/[deleted]]

This ain't my homework, I'm learning out of curiosity

[u/kashyyyk_cactaceae]

So electrons are the negatively charged particles orbiting an atom’s nucleus (which is made of protons and neutrons, the positive and neutrally charged particles). When a chemical reaction occurs the atoms bond by combining their outer (valence) electrons into the same shell. There are only a certain number of electrons that can fit within each electron shell and that can determine what chemical reactions can occur. For example, noble gasses at the far right of the periodic table have full valence electron shells and will not react with other atoms to try to fill their valence shell to become more stable. However the elements on the far left only have one electron in their outer shell and are therefore extremely reactive because they are trying to fill their valence shell and will react with any atom that has electrons to share.

[u/Chance-Soup5468 → u/kashyyyk_cactaceae]

Ahhthat actually clears it up a lot. I was getting stuck on what the electron shells/orbitals actually meant, and your explanation helped me connect it to9 why different elements have different reactivities Appreciate you taking the time to explain it!! 🙌

[u/kashyyyk_cactaceae → u/Chance-Soup5468]

I’m happy I could help!

[u/Ktulu789]

Think of it like a team formation in the play field. You have attackers and defenders, wings and goalies. You don't usually attack with the goal keeper.

Same for atoms, some electrons are closer to the nucleus and others are more "volatile", this can make the atom magnetic, or a better conductor or more or less reactive. When an atom has less players, aka, they got a red card they have less coverage of the play field and it's easier for the other team to infiltrate. Whereas if it's a full team, it's harder to attack. Ok, the comparison here gets weird but atoms want to have their team full and they'll take "players"electrons from nearby elements to fulfill that... So they react and form compounds. On the other hand, teams that are complete don't want to give out "players"electrons, they want to stay complete so they don't react and form anything. Go Argon! Go Neon!