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Topic: Can someone please explain to me about orbitals and shells?  (Read 2460 times)

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Offline OrionEmpire

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I don't fully understand them.

Basically, how do you determine which shell is valence?

Cuz like oxygen for instance, 6 electron outside, 2 inside but on charts it says valence is 2? Wtf?

Also orbitals, does each shell have 4 orbitals? Or does the whole atom have 4? Can it be less or more? Do all elements have 4? Or what ?

Also does anyone know a good video or visual way to show me this?


Offline OrionEmpire

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Unshared electrons, very confused
« Reply #1 on: May 22, 2016, 10:01:43 PM »
P has 5 valence electrons right, so with H, would the reaction with 4 orbitals, be 1 unshared electrons, or 2, with 3 used, ?

Like each orbital can only have 2 electrons, so could it be 2 paired, 2 paired, 1 , and then 1 unshared?

So confused...

Offline thetada

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Re: Unshared electrons, very confused
« Reply #2 on: May 23, 2016, 05:15:35 AM »
P has 5 valence electrons right, so with H, would the reaction with 4 orbitals, be...

When you say four orbitals, which do you mean? Are you talking about PH3 or PH4+?

Offline thetada

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Re: Can someone please explain to me about orbitals and shells?
« Reply #3 on: May 23, 2016, 05:19:47 AM »
There is a good intro to orbitals here: http://www.chemguide.co.uk/atoms/properties/atomorbs.html

The expression valence is used in different ways. You are right that oxygen has six valence electrons, but its valency is two because that is the number of electrons it needs to accept to gain noble gas configuration.

Offline mikasaur

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Re: Can someone please explain to me about orbitals and shells?
« Reply #4 on: May 23, 2016, 05:54:23 PM »
Here's another site that explains shells, subshells, and orbitals well: http://chemistry.stackexchange.com/questions/18466/difference-between-shells-subshells-and-orbitals

You might be confusing the term "valence" (and "valency") with "valence electrons". Valence electrons are the electrons in the outermost shell that are available for participation in chemical bonds.

The valency of an atom is a measure of its combining power with other atoms. In your example, Oxygen has 6 valence electrons (in the 2s and 2p subshells) but a valency of 2 -- it likes to accept two other electrons. Valency is important because it tells you how many bonds an atom likes to form, e.g. C makes 4 bonds, N makes 3, O makes 2, etc.

When learning this sort of stuff, I would stick with the period 2 atoms until you get comfortable with the concepts. They will always follow the octet rule. Atoms lower in the table do not always follow the octet rule (they have more than 8 electrons around the atom).

So if we use N instead of P, N has 5 valence electrons and a valency of 3, which means it will bond with 3 hydrogens. It will create ammonia -- NH3 -- by "sharing" 3 of its 2p electrons and "keeping" the other two. I'm sure our friend Enthalpy will chastise me for simplifying the concept of chemical bonds so much, but that's the 2-sentence explanation. ;)
Or you could, you know, Google it.

Offline OrionEmpire

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Re: Can someone please explain to me about orbitals and shells?
« Reply #5 on: May 24, 2016, 03:00:25 AM »
Thanks for the replies. But I figured it out today.

Basically what I was wanting to know was

K shell has 1s subshell with 1s orbital
L she'll has 2s, and 2p sub shells with 2s and 2p orbitals
M she'll has 3s, 3p, and 3d, orbitals
N she'll has 4s, 4p, 4d, and 4f orbitals.

I understand now that 1s orbital can hold a max of 2 electrons, each 2p 2as well, for a total of 6 max electrons, and then 10 in 4d, and 14 in 4f.

Thus k she'll max of 2 electrons. L she'll a max of 8, M she'll a max of 18, and N she'll a max of 32.

I found images of the orbitals and sheless and what not, and now fully understand the differences and aspects.

Sorry for the confusion. I study this s#*$ for fun. I never bothered with the fine details when I studied general chemistry. Now that I've moved on to organic chemistry, I see that most textbooks I'm using mention electron configuration alot, so I went ahead and learned those.


Offline Enthalpy

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Re: Can someone please explain to me about orbitals and shells?
« Reply #6 on: May 24, 2016, 01:30:53 PM »
Beware that the sequence of binding energy, and the sequence of orbital filling, does not follow the sequence 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f and so on.

Some general ideas there, not everything is correct (electrons "travel", mamma mia)
https://en.wikipedia.org/wiki/Electron_shell

Also, we'd like to understand the orbitals of any atom as if it were hydrogen, but the electrons interact, so the energy levels are not just scaled from those of hydrogen.

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