Geochemistry part 1 Flashcards
1
Q
Study of the nature and distribution of chemical elements in rocks and minerals
A
Geochemistry
2
Q
geochemist who used the word “geochemistry” in his book, data of geochemistry
A
Frank W. Clarke
3
Q
Father of Modern Geochemistry and crystal chemistry; proposed the classification of minerals according to preferred hosts
A
Victor M. Goldschmidt
4
Q
Rock-loving minerals
A
Lithophile
5
Q
Iron-loving minerals
A
Siderophile
6
Q
Ore-loving minerals
A
Chalcophile
7
Q
Gas-loving mineral
A
Atmophile
8
Q
A model of the evolution of the universe that prostulates its origin from a hot, dense mass that expanded rapidly and cooled
A
Big Bang Theory
9
Q
Clues of the expansion of the universe
A
- red shift (the use of doppler effect)
- cosmic microwave radiation
10
Q
The energy of radiation produced at a specific wavelength when the universe was at temp greater than about 3000k
A
Cosmic Background Radiation
11
Q
Hierarchy of the Universe
A
Clusters of Galaxy galaxy stars, pulsars, and black holes Planets Satelites Comets Asteroids Meteoroids Dust particles Molecules Atom of H and He
12
Q
The basic unit in heirarchy of the universe
A
Stars
13
Q
Produced by tcontraction of interstellar gases resulting in increase in temp
A
Main Sequence Stars
14
Q
High luminosity and high temp stars
A
Blue Giants
15
Q
Stars less massive than the sun
A
Red Dwarfs
16
Q
Bigger than the sun and is formed by depletion of H in the core during the main phase; the enrgy production shifted from the c ore to the outer shell
A
Red Giants
17
Q
End stage of stellar evolution;
A
Pulsars (neutron stars), white dwarf, black hole
18
Q
The theory that explains the complexation of material from the simple structure of H and deuterium (isotope of H)
A
Nucleosynthesis
19
Q
Most abundant elements in the universe
A
H and He
20
Q
The abundance of the first 50 elements decrease exponentially
A
Yaaaas
21
Q
The elements with even atomic numbers are more abundant than their immediate neighbors with odd atomic numbers
A
Remember
22
Q
Elements having atomic number higher than 50 are very low in abundance and do not vary appreciably with increasing atomic number
A
Ehem
23
Q
The abundances of Li, Be, and B are anomalously low compared to other elements of low atomic number.
A
Remember natin ito
24
Q
The abundance of Fe is notably higher than those of other elements with similar atomic numbers
A
!!!!!!!
25
Tc and Pm do not occur in the solars system because all of their isotopes are unstable and decay rapidly
Thechnetium
| Promethium
26
Diffuse mas of interstellar gas and dust
The solar nebula
27
Condensates accreted to form larger bodies as a result of selective adhesion caused by electrostatic and magenetic forces
Planetisimals
28
Even atomic numbers are greater in abundance than odd atomic numbers
Oddo-Harkins effect
29
Volatile-rich planetisimal composed of water, amonia, and other volatiles
Cometisimals
30
Chunks of rock from space that land on earth
Meteorites
31
Common minerals found in meteorites
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Kamacite
Taenite
Pyroxene
Olivine
Plagioclase
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32
Predominantly Ni-Fe alloys with minor amounts of other minerals such as troilite (FeS)
Iron Meteorites
33
Chiefly silicates, mostly ferromagnesians up to 1/4 metallic Ni-Fe types
Stone meteorites
34
Contains chondrules composed chiefly of silicates such as olivine, pyroxene, and plagioclase or glass
Note: it also has the same composition as the sun’s atmosphere
Chondrites
35
Important type of chondrites, because it brought water to earth 4.4 b yrs ago
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Carbonaceous chondrites
- a diverse class of chondrites, they arre important because of the insights they provide into the early history of the solar system
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36
Self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions
Stars
37
A stone meteorite with no chondrules and has the same composition as terrestrial mafic and ultramafic rocks
Achondrite
38
Extreterrestrial olivine
| A stony iron meteorite with equal proportions of pyroxene and olivine
Pallasites
39
Contains all the mass of an atom
Nucleus
40
How many times is the proton larger than the leectron
1825x
41
Any of the more than 1300 different atomic forms characterized by a distinct combination of protons and neutrons
Nuclide
42
Only 10 elements with atomic numbers. less than 27, show appreciable abundance
H, He, C, N, O, Ne, Mg, Si, S, FE
43
Elements adjacent to He are very low in relative abundance
Li and Be
44
Isotopes with mass numbers which are multiples of 4 (alpha particle mass number) have enhanced abundance
Alpha particle mass number
45
Plays the crucial part of overcoming the repulsive forces between protons, thus binding the nucleus to a tight structural unit
Neutrons
46
Refers to the number of proton in an atom of an element and serves to distinguish an element from another
Atomic Number (Z)
47
The ave mass of atoms of an element, the number of protons and neutrons in an atom of an element
Atomic weight (A)
48
Variation in atomic masses due to differences in the number neutrons of an element
Isotope
49
Nuclides having constant mass number but a different atomic weight
Isotones
50
Nuclides having the same atomic mass but different neutron number and atomic number
Isobars
51
A region surrounding the nucleus occupied by elevtrons having approx the same energy
electron shell
52
Charge deficiencies that result from substitution of ions of unequal charges must be compensated by a second substitution involving an ion having a different charge
Coupled substitution
53
Ions are attached on the charged surfaces of small ions; usually displayed by clay minerals
Adsorption
54
When minor element has the same charge and a similar atomic radius as the major eleemnt it is replacing
Camouflage
55
When a minor element enters a crystal preferentially because it has a higher ionic potential than the ions of the major element
Capture
56
The entry of a foreign ion that has a lower ionic potential that major ion because it has either a lower charge or a larger radius, or both;
Admission
57
Possesses lowest potential energy possible for the mineral
Stable
58
Possesses the highest potential enery
Unstable
59
Requires an energy hurdle to put in the most stable form or of lower potential energy
Metastable
| Note: due to activation energy it decides if maging stable sya or hindi
60
Shows the ranges stability in pressure-temp space parameters
Phase diagrams
61
Areas representing the range of applied pressure and temp in which a mineral may exist in his stable form
Stability fields
62
The line separating the various stability fields and defines a restricted set of circumstances under which the separated phases coexist in equilibrium
Phase boundary
63
Energy required for transformation to take place and is represented by the height of the energy hurdle
Activation energy
64
Concerned on the free energy changes associated with chemical equilibrium between phases, and provides the tools for working out which mineral assemblages will be stable under which conditions
Thermodynamics
65
Deals with the mechanics of the reactions that lead to equilibrium, and the rates at which they occur
Chemical Kinetics
66
A part of the universe which we wish to confine attention or whose properties are under consideration
System
67
A system that is free to exchange both matter and energy to the surrounding
Open system
68
A system sealed with respect to the transfer of matter, but that can still exchange energies with its surrounding
Closed system
69
System that do not exhange matter nor energy to its surrounding
Isolated system
70
A part of the system occupying a specific volume and having uniform physical and chemical characteristic which distinguishes it from all other parts of a system
Phase
71
Comprises the minimum number of chemical species required to specify completely the compositions of all the phase present
Components
72
All parts of the system have the same temp; there is no transfer of heat
Thermal equilibrium
73
The distribution of components among the phases of a system has become constant, showing no net change with time
Chemical equilibrium
74
The diffusion rate of an element in and out of the crystal are unequal
Disequilibrium
75
Element present the flux of atoms across the crystal boundary is the same in both directions resulting in zero flow, and no change of composition in time
Equilibrium
76
A formula which expresses the number of phases that can coexist in mutual equilibrium, in terms of the number of components in the system and another property of the equilibrium called variance (degrees of freedom)
The Gibbs Phase Rule
| By J. Willard Gibbs
77
0 degree of freedom
Means that the three phase equilibrium assemblage completely constrains the state of the system to a particular combination of P and T
Invariant
78
1 degree of freedom
| Indicates that the state of the system is only unconstrained in one direction which is along the phase boundary
Univariant
79
2 degrees of freedom
| The pressure and temp can vary independently without upsetting the equilibrium phase
Divariant
80
The locus of temp below which a given substance is completely solid
Solidus
81
The temp above which a material is completely liquid, and the max temp which crystals can coexist with the melt in thermodynamics
Liquidus
82
The point on the phase diagram where the max number of allowable phase are in equilibrium
Eutectic Point (invariant)
83
The point on a phase where a reaction takes place between a previously precipitated phase amd the liquid to produce a new solid phase.
Peritectic Point
84
A phase that has a composition intermediate between two other phases
Intermediate compound
85
Melting where in a phase melts to a liquid with the same composition as the soild
Congruent melting
86
Melting where in a phase melts to a liquid with composition different from the solid and produces a solid of different composition to the original solid
Incongruent Melting
87
Exsolution feature formed by slow cooling
Widmanstatten structure
88
First coined the word geochemistry
Friedrich Schonbeim
89
Meteorites with Equal amounts of silicate and Ni-Fe alloys
Stony-Iron Meteorites
