Download STRUCTURE OF ATOMS

STRUCTURE OF ATOMS
STRUCTURE-CONTD
MODEL OF AN ATOM-Fig
MINERALS
PERIODIC TABLE
ATOM & COMPOUND
ENERGY LEVEL
ENERGY LEVEL DIAGRAM-H ATOM
ENERGY-LEVEL DIAGRAM – He ATOM
ENERGY-LEVEL DIAGRAM – Li ATOM
ENERGY-LEVEL DIAGRAM – Na ATOM
IONS
OCTET RULE
IONIC AND COVALENT BONDING


ION
STRONG TENDENCY TO LOSE ELECTRONS/ STRONG
TENDENCY TO GAIN ELECTRONS  IONIC BONDING
COVALENT BONDING:
*SHARING OF ELECTRONS
*ATOMS WITH 3, 4, OR 5 ELECTRONS SHARE WITH OTHER
SIMILARLY EQUIPPED ATOMS
*COVALENT BONDS ARE GENERALLY STRONGER THAN ANY
OTHER BOND
IONIC BONDING
METALLIC & INTERMOLE. BONDING
HYDROGEN BOND:
MINERAL STRUCTURE:
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•
•
•
CRYSTALS ---- A REGULAR GEOMETRIC SHAPE
CRYSTAL STRUCTURE ---- ORDERLY ARRANGEMENT
OF IONS OR ATOMS INTO A LATTICE WORK OF
REPEATED THREE – DIMENSIONAL UNITS
GLASS IS NOT A MINERAL – SUDDEN COOLING OF
MOLTEN ROCK RESULTS IN LACK OF ORDERLY
ARRANGEMENT
MINERALOIDS: CONSTANT COMPOSITION BUT, NO
SPECIFIC CRYSTAL STRUCTURE
EX: OBSIDIAN ( A NATURAL GLASS )
NaCl STRUCTURE
MINERALS DEPEND ON
GRAPHITE STRUCTURE
DIAMOND STRUCTURE
ELEMENTAL ABUNDANCE
POLYMORPHISM
DIAMETERS OF IONS
MINERAL IDENTIFICATION:
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•
FIELD
LABORATORY
COLOR: LEAST RELIABLE IDENTIFYING CHARACTERISTIC
LUSTER: DESCRIBES HOW A MINERAL’S SURFACE REFLECTS LIGHT
( VIBRATING ELECTRONS EMIT A DIFFUSE LIGHT, GIVING
METALLIC SURFACES THEIR CHARACTERISTIC SHINY LUSTER)
STREAK: COLOR OF A MINERAL IN ITS POWDERED FORM – OFTEN A
MORE ACCURATE INDICATOR OF MINERAL IDENTITY.
MOH’S SCALE
MOH’S HARDNESS SCALE:
SCALE-CONTD.
CLEAVAGE
SMELL & TASTE
SILICATES:
~ 90% OF THE WEIGHT OF THE EARTH’S CRUST
O – PRIMARY ELEMENT
_ READILY ACCEPTS ELECTRONS TO FORM NEGATIVE
IONS
-
Si - 2ND MOST ABUNDANT ELEMENT
COMPATIBLE WITH OXYGEN
NUMBER OF OXYGEN IONS SHARED BY A TETRAHEDRON (Si/O RATIO)—TYPE OF SILICATE AND CRYSTAL
STRUCTURE
Si/O = 4 ( IF TETRAHEDRON DOES NOT SHARE
OXYGEN ION)
Si/O = 2 (IF ALL OXYGEN IS SHARED)
TETRAHEDRAL SILIC. STRC.
SINGLE SILICATE STRUC.
DOUBLE CHAIN SI STRUC.
SHEET SI STRUCTURE
FRAMEWORK SI STRUCT.
DRY CLAY MINERAL STRUC
EXPANSION DUE TO ADSOR.
Geology at a Glance
Geology at a Glance (continued).