Camosun College GEOS 250 Lectures: 9:30-10:20 M T Th F300 Lab: 9:30-12:20 W F300

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Introduction to Mineralogy Dr. Tark Hamilton Chapter 3: Lecture 7 The Chemical Basis of Minerals (sizes, shapes & directions) Camosun College GEOS 250 Lectures: 9:30-10:20 M T Th F300 Lab: 9:30-12:20 W F300

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Introduction to Mineralogy Dr. Tark Hamilton Chapter 3: Lecture 7 The Chemical Basis of Minerals (sizes, shapes & directions). Camosun College GEOS 250 Lectures: 9:30-10:20 M T Th F300 Lab: 9:30-12:20 W F300. Controls of Size in Atoms & Ions. In lone atoms (few and far between): - PowerPoint PPT Presentation

Transcript of Camosun College GEOS 250 Lectures: 9:30-10:20 M T Th F300 Lab: 9:30-12:20 W F300

Introduction to MineralogyDr. Tark Hamilton

Chapter 3: Lecture 7The Chemical Basis of Minerals

(sizes, shapes & directions)

Camosun College GEOS 250

Lectures: 9:30-10:20 M T Th F300

Lab: 9:30-12:20 W F300

Controls of Size in Atoms & Ions

• In lone atoms (few and far between):– Electrons are attracted by Z = Atomic #

• 92U1s < 1H1s

– Electrons in same shell repel each other• 9F > 3Li

– Heavier atoms/ions are bigger down groups• 56Ba > 12Mg

• +/- charges of nearest neighbours count– Al+3 is smaller in (AlO4)-5 than with (AlO6)-9

Ice - Covalent BondedMineral & Rock: H2O

1 AngstromStrong molecular bonds

within waters

1.8 AngstromWeak Hydrogen bonds

between waters

Open Channels(low density)

Each Oxygen isTetrahedrally coordinated

by 4 Hydrogens

H-O-H bond angle104.5°

(Tetrahedral = 109.5°

High OLow O

There are many Higher Pressure Polymorphs!

Sub-Atomic Physicsfor

Dummies & Mineralogists

The Bohr Hydrogen Atom

Explains H emission lines Classical orbits decay

Better thanRutherford’s

Plum PuddingModel

Elements & Isotopes

CarbonAtomic # 6

At.wt. 12.011

NitrogenAtomic # 7

At.wt. 14.0067

OxygenAtomic # 8

At. wt. 15.9994

Stable Isotopes

Geologically Common & Important Elements in Minerals

Major Elements: Al, Ar, Ca, C, H, K, Fe,Mg, Mn, N, Na, O, P, S, Si, Ti

(16)

Minor Elements: As, B, Ba, Be, Bi, Br, Ce,Cd, Cs, Cl, Cr, Co, Cu, F, He, La, Pb, Hg, Mo,Nb, Ni, Ra, Rn, Sc, Se, Sr, Sn, W, V, Y, Zn, Zr

(32)

Trace Elements: Ag, Au, Dy, Eu, Ga, Gd,Hf, Ho, I, Ir, Li, Lu, Nd, Os, Pd, Pt, Rb, Rh,

Sm, Ta, Tb, Te, Tl, Th, Tm(25)

Electrons Locations as Schroedinger’s Wave Functions

S Orbital

S Orbital Radius

Subshell Orbital Geometries

S1,2,3 Orbitals

P2 x y z Orbitals

D3 Orbitals

Orbital Quantum Numbers& Order of Filling Sub-shells

Spectral Line Names:

s – Sharp

p – Principal

d – Diffuse

f - Fundamental

Quantum Numbers for Dummies & Mineralogists

n Principal Quantum # = size of atom& row in periodic table

K, L, M: important shells forX-ray generation & identification

s, p, d, f – Electron energy levelsorbital shapes & directions

Every electron in every elementhas a unique set of quantum numbers

& an energy level all its own.

Electron jumps = Δ energy, photons

Quantum Numbers = Electron E’s

Magnetic Spin Quantum #Stern-Gerlach Experiment

Spin +/- ½

Magnetic Field & Induction

Deflected Ag beamby strong

Magnetic fieldGave 2 spotsHalf filled 5s1

Pauli Exclusion Principle:No 2 electrons may have identical values

for all quantum numbers

Schroedinger’s Quantum Numbers• n – principal shell (distance from nucleus)• l – azimuthal, shape of orbital• ml – magnetic, direction/orientation of orbital

Spin Quantum Number (empirical)• ms – spin magnetic

• Pairs of electrons in subshells: s, p, d, f differ in the sign of their spin magnetic #

Elements and Ions

Low Ionization potential forms Ions easily

Lone electrons ionize easily

Noble gases need X-rays to ionize

Electronegativity attracts electronsto atom in covalent bonds

Geeze-Louise! This looks like thelist of major & minor elements!