Inner electron shell can hold THREE electrons?

rathbaner

My daughter, 14, is doing junior cert science and says that she was taught this at school by her science teacher. She showed me her diagram of a Carbon atom showing 6 electrons, three on each shell (level). She insisted that I was wrong when i told her that the electrons should be distributed with two on the inner shell and 4 on the outer.
Her diagram of a Lithium atom showed a single shell with three electrons.

It has made me doubt what I was taught.

Has basic atomic structure changed so fundamentally since the 1970s?

Morbert

rathbaner wrote: »

My daughter, 14, is doing junior cert science and says that she was taught this at school by her science teacher. She showed me her diagram of a Carbon atom showing 6 electrons, three on each shell (level). She insisted that I was wrong when i told her that the electrons should be distributed with two on the inner shell and 4 on the outer.
Her diagram of a Lithium atom showed a single shell with three electrons.

It has made me doubt what I was taught.

Has basic atomic structure changed so fundamentally since the 1970s?

That Lithium diagram is definitely wrong. There are two electrons in the first shell, and one electron in the second shell.

El Siglo

I did chemistry about six years ago and no way is that right, it has always been two on the first shell and then the one in the second etc... Teacher is wrong.

SOL

It is definitely two in the first shell and one in the second for Lithium
and 2+4 for carbon

Baralis1

The inner shell only holds two electrons. Its a fundamental atomic property. That teacher should not be teaching chemistry if he/she doesn't know that!

FISMA

Correct, two in the first, no matter what, if you have two that is.

Be gentle with the teacher, don't start a pissing match. If the teacher is new or had to teach a subject that they themselves may not have majored in, they may be a bit rusty. In the end, they may be doing their best.

Have a chat aside, not in front of the class and make your case.

sponsoredwalk

Either your daughter got confused and meant lithium has 3 electrons,
period! (which it does), or her teacher simply used the wrong word
when explaining the electron set up. Seeing as there are 3 electrons
in lithiums shellS it's most likely explained by a simple grammatical
mistake. Ask your daughter to go in tomorrow, after you've taught
her this & shown her the picture, to clarify things with the
teacher.

ApeXaviour

rathbaner wrote: »

Has basic atomic structure changed so fundamentally since the 1970s?

No

ride-the-spiral

Wouldn't that change all of the atomic properties? Lithium wouldn't be reactive it had a full shell with 3 electrons.

Does she not have a science book she can consult? It's the same course that I did.

franb7111

your right, the first shell (1s shell) or energy level of the carbon atom is made up of one orbital contains 2 electrons,orbitals can only contain 2 electrons. The next shell or energy level is made up of one (2s) orbital and 3 (2p) orbitals, these orbitals mix together to form 4 equivalent (sp3) orbitals each of these orbitals contains 1 electron making up 4 electrons in the outer shell. I think the teacher needs to brush up on their basic chemistry

Delphi91

Without going into the idea of orbitals and sub-orbitals (which is not needed for Junior Cert), the easiest way of calculating the number of electrons on a given shell is to use the formula 2n^2 where n is the shell number:

n = 1 (first shell)... 2 (1)^2 = 2 1st shell holds a maximum of 2 electrons

n = 2 (second shell)...2 (2)^2 = 8 2nd shell holds a maximum of 8 electrons

n = 3 (third shell)...2 (3)^2 = 18 3rd shell holds a maximum of 18 electrons

etc...

In the cae of carbon, which has 6 electrons, they fill the first shell (using up 2 electrons), which leaves 4 for the second shell, so the "electronic configuration" is 2, 4.

I always teach the filling of electrons into shells by using the analogy of a fountain. The water pours into the top of the fountain; when that bowl is full, the water overflows into the next bowl until it is full, and so on....

RMD

I'd say it was actually just poor communication or poor examples used by the teacher in this case and thus your daughter might have misinterpreted what the teacher meant.

Every person who has studied Chemistry past Junior cert level will know that N1 = 2, N2 = 8, N3 = 18 and so on. So I highly doubt the teacher taught it was N1 = 3, if so they shouldn't be allowed discuss the subject let alone teach it.

tricks

That's quite worrying! It definitely only holds two electrons. Are you sure she isn't taking the diagrams down incorrectly? Check her science book if she has one, if not perhaps get her to mention it to the teacher.

craggles

As a chemist this thread blows my mind

Capt'n Midnight

It's OK to pair off electrons in shells.

Have they been educated about valency electrons and how the nobel gas electron configuration is for most intents inert and they just have to worry about electrons in shells outside that (yes I know that a few compound exist)



Lithium with 3 electrons in a shell *grabs pitchfork, joins mob*

JakeH1979

franb7111 wrote: »

your right, the first shell (1s shell) or energy level of the carbon atom is made up of one orbital contains 2 electrons,orbitals can only contain 2 electrons. The next shell or energy level is made up of one (2s) orbital and 3 (2p) orbitals, these orbitals mix together to form 4 equivalent (sp3) orbitals each of these orbitals contains 1 electron making up 4 electrons in the outer shell. I think the teacher needs to brush up on their basic chemistry

And so do you!
Carbon does form Sp3( which forms 4 sigma bonds), Sp2(which will form one sigma and one pi bond) and Sp(which will form one sigma and two pi bonds) hybridised orbitals but only during bonding e.g in methane carbon is Sp3 hybridised i.e. 1s2 2s1 2px1 2py1 2pz1 which occurs to accomodate the bondig of four hydrogen atoms. Anyway this all involves advanced organic chemistry which i wont go into.Carbons ground state configuration is 1s2 2s2 2px1 2py1.

Professor_Fink

ride-the-spiral wrote: »

Wouldn't that change all of the atomic properties? Lithium wouldn't be reactive it had a full shell with 3 electrons.

Worse still, it would require electrons be spin-1, which would screw up all of particle physics.

franb7111

JakeH1979 wrote: »

And so do you!
Carbon does form Sp3( which forms 4 sigma bonds), Sp2(which will form one sigma and one pi bond) and Sp(which will form one sigma and two pi bonds) hybridised orbitals but only during bonding e.g in methane carbon is Sp3 hybridised i.e. 1s2 2s1 2px1 2py1 2pz1 which occurs to accomodate the bondig of four hydrogen atoms. Anyway this all involves advanced organic chemistry which i wont go into.Carbons ground state configuration is 1s2 2s2 2px1 2py1.

Of course you are right, i stand corrected i got bit ahead of myself, its been a while since i did electronic cofigs, or saw a single carbon atom for that matter, but its hardly advanced organic chemistry!!!
Also i think you'll find that the sp2 hybrid forms 3 equivalent sp2 bonds, the pi bond is formed by the overlap of (2) p orbitals, similarly, the sp forms 2 equivalent sp bonds the 2 pi bonds are again formed by the over lap of 2 pairs of p orbtals, so i believe it is you that needs to brush up on your "advanced orgainc chemistry"

JakeH1979

franb7111 wrote: »

Of course you are right, i stand corrected i got bit ahead of myself, its been a while since i did electronic cofigs, or saw a single carbon atom for that matter, but its hardly advanced organic chemistry!!!
Also i think you'll find that the sp2 hybrid forms 3 equivalent sp2 bonds, the pi bond is formed by the overlap of (2) p orbitals, similarly, the sp forms 2 equivalent sp bonds the 2 pi bonds are again formed by the over lap of 2 pairs of p orbtals, so i believe it is you that needs to brush up on your "advanced orgainc chemistry"

It was advanced organic chemistry when i studied it a number of years ago in the fourth year of my degree. It is easy when you can look it up before you edit your post but i tried to answer from memory so i left out some bits. You obviously took offence where none was intended but if you feel that way its your problem. The crux of my point which you missed was the electronic configuration of ground state carbon where did i mention i saw a single carbon atom.

franb7111

JakeH1979 wrote: »

It was advanced organic chemistry when i studied it a number of years ago in the fourth year of my degree. It is easy when you can look it up before you edit your post but i tried to answer from memory so i left out some bits. You obviously took offence where none was intended but if you feel that way its your problem. The crux of my point which you missed was the electronic configuration of ground state carbon where did i mention i saw a single carbon atom.

Hi jake the only reason i mentioned a single carbon atom was more or less to say the same thing as you that i studied it a no. of years ago( about 20) and that i havn't thought about it really since i was thought it .its not something that has that use much . However i didn't need look up hybridization as you suggested, you could of pointed out my error and left it at that but if you are going to go on and correct me you should at least get it right. Also i'd say if think back to your degree you learnt about it in first year.