Chem 125 Lecture 29/6/02

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What Lewis Added

Text p. 16“empirical rules for assessing the relative importance of the resonance structures of molecules and ions.

1. Resonance structures involve no change in the positions of nuclei; only electron distribution is involved.

3. The more important structures are those involving a minimum of charge separation, particularly among atoms of comparable electronegativity. Structures with negative charges assigned to electronegative atoms may also be important.

2. Structures in which all first-row atoms have filled octets are generally important; however, resulting formal charges and electronegativity differences can make appropriate nonoctet structures comparably important.LORE

Is it True?

Force Laws

Levitator by Martin Simon (UCLA)

Eppur sta fermo

In systems governed byinverse-square force laws

there can be no local minimum (or maximum)

of potential energy.

Earnshaw's Theorem(1839)

Visualizing Earnshaw - Coulomb's Electrostatics

Faraday/Davy/Phillips

A positive particle has a local maximum or minimum of energy only at the location of

another charged particle, never in free space.

In systems governed byinverse-square force laws

there can be no local minimum (or maximum)

of potential energy.

Earnshaw's Theorem

The only stationary pointsare saddle points.

"I have ever since regarded [the cubic octet]as representing essentially the arrangement

of electrons in the atom"

G. N. Lewis (1923)

Was Lewis ignorant ofEarnshaw's Theorem?

J.J. Thomson (1856-1940)

Electron (1897) Plum-Pudding Atom

"[We can] solve the special case where the corpuscles are

confined to a plane."

Thomson's Model of Electron Configuration

"consider the problem as to how 1…2…3…n corpuscles would arrange themselves if placed in a sphere filled with positive electricity of uniform density…"

“distributed in the way most amenable to

mathematical calculation”

Vortex Lattice Models (Greg Blonder www.genuineideas.com)

"[We can] solve the special case where the corpuscles are

confined to a plane."

Thomson's Model of Electron Configuration

"consider the problem as to how 1…2…3…n corpuscles would arrange themselves if placed in a sphere filled with positive electricity of uniform density…"

"the equilibrium of eight corpuscles at the corners of a cube is unstable."

"I have ever since regarded [the cubic octet]as representing essentially the arrangement

of electrons in the atom"

G. N. Lewis (1923)

Was Lewis ignorant ofEarnshaw's Theorem?

Conclusion of

Valence and the Structure of Atoms and Molecules G. N. Lewis (1923)

"if we use the electron as a test charge to determine the properties of the simplest possible electric field,

namely, the field about a hydrogen nucleus, we appear to find that this field is not a continuum

but is strikingly discontinuous."

The Future of the Quantum TheoryThe Discontinuity of Physico-Chemical Processes

The Electron in Chemistry

J. J. Thomson (1923)

… if [electron-nuclear attraction] were to vary strictly as the inverse square of the distance we know by Earnshaw's theorem than no stable configuration in which the electrons are at rest or oscillating about positions of equilibrium is possible ...

… then a number of electrons can be in equilibrium about a positive charge without necessarily describing orbits around it.

I shall assume that the law of force between a positive charge and an electron is expressed by the equation

F =Eer2 1−

cr

⎛ ⎝

⎞ ⎠

cr

Quantum Mechanics (1926)

reformulated kinetic energyto explain electron clouds and produce an "inverted"

plum-pudding atom.

Cubic octets and ad hoc force lawssoon disappeared from conventional

Chemistry and Physics

But shared-pairs and lone-pairsbecame useful tools for discussing

structure and bonding.

How do you know?

Might there still be shared-pair bonds

and lone pairs?

By Seeing? Feeling?

InconceivablySmall?

OCCULT CHEMISTRY

A SERIES OF

Clairvoyant Observations on theChemical Elements

BY

ANNIE BESANT, P.T.S.

AND

CHARLES W. LEADBEATER

Reprinted from the Theosophist.

THEOSOPHIST OFFICE, ADYAR, MADRAS, S.

THEOSOPHICAL PUBLISHING SOCIETY, LONDON AND BENARES CITY.

1909 (105 pp.)

1919 (123 pp.)

1951 (400 pp.)

Mrs. AnnieBESANT

P.T.S.(1847-1933)

CuruppumullageJINARAJADASA

P.T.S.(~1877-1953)

"Bishop"Charles WebsterLEADBEATER

(1847 - 1932)

The Occult Chemists (1895-1932)

H O N (1895)18 290 261

Anu

. 25 .Anavah skandhashcha"anu and skandha"

These 42 Aphorisms have inspired more than 100 Commentaries

•

"(Matter has 2 chief forms:) atom and molecule." G. R. Jain (1942)

Tattvartha Sutra, Umaswami (135-219 A.D.) Chapter V

"Matter exists in the form of indivisible elementary particles and their combinations" J. L. Jaini (1920)

Helium72

Lithium127

Iron1008

Neon360

Sodium418

Occult Atoms

5dorbital

Na2CO3(1924)

"note that this trian-gular arrangement of O3 has just been deduced by Bragg from his X-ray analysis of Calcite"

Benzene(1924)

"each of the three valencies of each Carbon are satisfied by Hydrogen, and the fourth valency, which some have postulated as going to the interior of the molecule, does actually do so."