/sci/ - Science & Math

[Anonymous No.2020048]

Semi-Easy chem questions here

What exactly drives atoms to have a full valence shells? As in why do they want full ns2np6 orbitals (or full d orbital), especially interested in the case that where the atom is already at a balanced charge (next question is semi-related)

Why do covalent bonds happen? I understand Ionic compounds form because Ions of opposite charges attract, but why do things like O2 or H2 occur? (something with electron spin?)

I would love detailed answers, my chem book doesn't go into good detail and I never have good luck with science on wiki.

Thanks in advanced! (Assuming someone actually answers)

[fS !!oSgu8W0zL9U No.2020075]

>>2020048
/sci/ now realizes that you are a sophomore in high school.

ub&

[Anonymous No.2020082]

>>2020075

Doesn't explain questions at all
Glad you are smarter than a sophomore in hs

[fS !!oSgu8W0zL9U No.2020091]

>>2020082
lol "smarter"

[Anonymous No.2020125]

>>2020091
Omg go back to /b/ faggot troll.

Does you have an answer? Probably not, you know why? Because you don't know either.

[Anonymous No.2020139]

Oookay,

Any non-trolls that can answer?
I took basic chem in hs, never took AP because I was too busy with physics and multi-variable. This is a gen-chem1 class as a freshman at UCSB.

[Anonymous No.2020151]

Hund's rule: Filled shells are more stable.

Depends on the types of bonds: hydrogen bonds, dipole interactions, london forces, basically sharing electrons allows for a lower energy state = more stable. By thermodynamics the universe and its constituent matter tends to seek less complexity.

[Anonymous No.2020155]

>>2020151

Also forgot to mention the Pauli exclusion principle.

[Anonymous No.2020159]

atoms don't "want" a full valence electron shell, the reason it occurs is because it is downhill in energy to having unpaired electrons in valence shells. Basically elements form because they are lower in energy and as such can happen spontaneously without addition of energy. Same reason can be applied to why breaking bonds requires energy, you need to add energy to get the valence electrons in the same spin which causes a higher anti-bonding so the elements would rather exist seperately as ions.

TL;dr: Lower the energy of the elements.

[Anonymous No.2020167]

Simple answer: electrons will seek the lowest potential, much the same way that a rock will tend to rest on the ground rather than in the air. Sometimes seeking the lowest potential involves flitting about between two separate nuclei.

[Anonymous No.2020210]

>>2020151
>>2020159
Thanks for the answers guys, but this is only about as much as this book says.

>>2020167
I think this is getting closer to the answer I am looking for. I am also in a lower division E&M class, I am trying to use coulombs law to check the forces between two H atoms (with 1 proton/electron). The way I have been looking at it so far is this: (where P and e are proton and electron)

P1--e1--e2--P2

According to my calculations the repelling force between the two electrons is always more than the attractive force between the electrons and the protons.

The reason I am using this model is because my chem book says that the electrons spend the most time between the two protons of the H nuclei.

[Anonymous No.2020278]

>>2020210
At this point, you're either going to have to start fudging some equations, or get your quantum on.

For starters, you'll want to focus on equipotential regions more than forces. Newtonian mechanics won't work here; in fact, this is the problem that spurred QM in the first place.

Second, when considering the potentials, it may be more helpful to consider just the protons' effects on a single electron. It's too small of a region to consider canceling out the charges (the way you might if you are considering the behavior of the outer electron of a heavier atom, like say potassium), and it's not really appropriate to model the system as a dipole either - at this level the electrons are more like a smear - a matter-probability wave. Of course, for a classical generalization, this becomes too complex, and just considering a charged volume representing the "other electron" doesn't yield any useful insights.

[Anonymous No.2020342]

>>2020278
Thanks for this! After reading this I for some reason finally pictured what was going on in my head. I think my problem was (like you implied) that I was treating electrons kind of like a stationary particle while ignoring its wave properties. I watched a few youtube vids and I get it now :D

/thread I suppose