Re: pinhole 8 valence electrons and the area of a circle

Date view Thread view Subject view Author view Attachment view

From: Paul Doherty (pauld@exploratorium.edu)
Date: Thu Jan 23 2003 - 07:58:16 PST 

Message-Id: <l03110731ba55bfb4b35c@[192.174.3.125]>
Date: Thu, 23 Jan 2003 07:58:16 -0800
From: Paul Doherty <pauld@exploratorium.edu>
Subject: Re: pinhole 8 valence electrons and the area of a circle

Hi Jhumki

In answer to 2.)

Bohr hypothesized that electrons around atoms behaved as sine waves. The
wavelength of the sinewave was inversely proportional to the momentum of
the electron. there were certain radii of orbits at which an inttergral
number of sine waves just fit the circle around the atom. The electrons
were stable at these radii, and so the energy levels of hydrogen were
determined.

Schroedinger used three dimensional waves for electrons around atoms to
solve his equations, the spherical legendre polynomials. The simplest of
these orbitals is a sphere, the 1 s orbital (it holds two electrons because
electrons can have two spins. up and down) The next one has a shape of r
=sin^2 (T) rotated about the T = 0 axis to make the classic P orbital.
There are 3 ways to arrange P orbitals so they don't overlap by rotating
the sin^2 about each of the 3 coordinate axes x,y, and z. each holds two
electrons.

So with two ellectrons from the S orbital and 6 from the three different P
orbitals we get 8 total electrons beloved by chemists.

(The shapes continue with sin^4 T making the d orbitals, and sin^6 T making
the f. There are 5 different ways to arrange d orbitals so they don't
overlap so they can hold 10 electrons. and so on.)

Paul D

My keybooard is doubling chharacters sorry.

>
>
>A couple of questions about which I wondered for a while:
>
>
>
>1) Why is the area of a circle calculated using the formula (pi)(r^2)?
>Where does this formula come from?
>
>
>
>2) Why are atoms stable generally stable when they have 8 valence
>electrons? What is magical about a noble gas configuration? Why do certain
>orbitals (s,p,d,f, etc.) only allow certain numbers of electrons? What
>determines this?
>
>
>
>Thanks!
>
>
>
>Jhumki
>
>
>
>Help STOP SPAM with <http://g.msn.com/8HMMENUS/2731>the new MSN 8 and get
>2 months
>FREE*---------------------------------------------------------------------------
>To unsubscribe from pinhole, send an email to requests@exploratorium.edu
>with the words 'unsubscribe pinhole' (without the quotes) in the SUBJECT
>of the email.To subscribe to the digest and only get 1 combined message a
>day, send an email to requests@exploratorium.edu with the words 'subscribe
>digest pinhole' (without the quotes) in the SUBJECT of the email.Check
>out what your colleagues have written on Pinhole in the Pinhole archives
>at: http://saturn.exploratorium.edu/ti/alumni/pinhole.html
>---------------------------------------------------------------------------

Date view Thread view Subject view Author view Attachment view

This archive was generated by hypermail 2.1.3 : Mon Aug 04 2003 - 16:18:12 PDT