Transcript First Energy Level

GALLIUM
Group13
Siti Rohmatikah (10503046)
Rasminda Senovita (10503047)
Nurrahmi H (10503048)
Dani Setiawan (10503049)
Overview of Gallium
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Origin of name:
– L. Gallia, France
– Latin, gallus, a translation of Lecoq, a cock
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History:
– Predicted and described by Mendeleev as ekaaluminum (Ea)
– discovered spectroscopically by Lecoq de Boisbaudran in
1875
– in the same year Lecoq obtained the free metal by electrolysis
of a solution of the hydroxide in KOH
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Sources:
– found throughout the crust in minerals like bauxite, germanite
and coal
Atomic Structure of Gallium
Number of Energy Levels: 4
First Energy Level : 2
Second Energy Level : 8
Third Energy Level : 18
Fourth Energy Level : 3
Crystal Structure of Gallium
Orthorombic
Physical Properties
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Atomic Mass Average: 69.723
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Melting Point
Boiling Point
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Conductivity :
– Electrical : 0.0678 106/cm
– Thermal
: 0.406 W/cmK
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Density
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Description:
– Soft silver-white metal
– Properties similar to aluminum
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Enthalpy of Atomization : 276.1 kJ/mole
Enthalpy of Fusion
: 5.59 kJ/mole
Enthalpy of Vaporization : 256.1 kJ/mole
: 29.9°C
: 2403°C
: 5.907g/mL @ 300K
Chemical Properties
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Electron Work Function : 4.2eV
 Electronegativity
: 1.81 (Pauling)
 Heat of Fusion
: 5.59 kJ/mol
 Ionization Potential:
– First
– Second
– Third
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: 5.999
: 20.51
: 30.71
Valence Electron Potential : -69.7 eV
Chemical Reactions
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with air:
2 Ga(g) + N2(g) → 2 GaN(s)
with water:
Ga3+(aq) + H2O(l) → Ga(OH)2+(aq) + H+(aq)
with acids:
Ga(s) + 3 HCl(aq) → GaCl3(aq) + 3 H+(aq)
with bases:
GaCl3(aq) + 4 LiH(s) → LiGaH4(aq) + 3 LiCl(aq)
with halogens:
3 Ga(s) + AlF3(aq) → 3 GaF(aq) + Al3+(aq)
Isotopes & Abundances
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only present due to small traces in the natural
environment, in water, and in residue on
vegetables and fruits
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Isotopes’ Half Life
– Ga-66 : 9.5 hours
– Ga-67 : 3.3 days
– Ga-68 : 1.1 hours
– Ga-69 : Stable (60.1%)
– Ga-71 : Stable (39.9%)
– Ga-72 : 14.1 hours
Use of Gallium
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Semiconductors: solid-state devices such as ICs, transistors
(GaAs)
component in low-melting alloys
substitutes for mercury dental amalgams
high-temperature thermometer
laser diodes (GaN)
LEDs
solar cells
LCDs and FPDs
used to locate tumors
used to detect solar neutrinos
Health Effects
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pure gallium is not a harmful substance
for humans to touch
 gallium radioactive compound, gallium
[67Ga] citrate, can be injected into the
body and used for gallium scanning
without harmful effects
 should not be purposefully consumed in
large doses
 some gallium compounds can actually be
very dangerous. For example: GaCl3
Environmental Effects
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gallium is used to hold some nuclear bomb pits
together
when the pits are cut and plutonium oxide
powder is formed, the gallium remains in the
plutonium
the plutonium then becomes unusable in fuel
because the gallium is corrosive to several other
elements. If the gallium is removed, however, the
plutonium becomes useful again
the problem is that the process to remove the
gallium contributes to a huge amount of pollution
of water with radioactive substances