G A L L I U MG A L L I U M

Group13

Siti Rohmatikah (10503046)Rasminda Senovita (10503047)

Nurrahmi H (10503048)Dani Setiawan (10503049)

Overview of GalliumOverview of Gallium

Origin of name:– L. Gallia, France– Latin, gallus, a translation of Lecoq, a cock

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

Sources: – found throughout the crust in minerals like bauxite, germanite

and coal

Atomic Structure of GalliumAtomic 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 GalliumCrystal Structure of Gallium

Orthorombic

Physical PropertiesPhysical Properties Atomic Mass Average: 69.723

Melting Point : 29.9°C Boiling Point : 2403°C

Conductivity :– Electrical : 0.0678 106/cm– Thermal : 0.406 W/cmK

Density : 5.907g/mL @ 300K

Description: – Soft silver-white metal– Properties similar to aluminum

Enthalpy of Atomization : 276.1 kJ/mole Enthalpy of Fusion: 5.59 kJ/mole Enthalpy of Vaporization : 256.1 kJ/mole

Chemical PropertiesChemical Properties

Electron Work Function : 4.2eV Electronegativity : 1.81 (Pauling) Heat of Fusion : 5.59 kJ/mol Ionization Potential:

– First : 5.999– Second : 20.51– Third : 30.71

Valence Electron Potential : -69.7 eV

Chemical ReactionsChemical Reactions

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 & AbundancesIsotopes & Abundances

only present due to small traces in the natural environment, in water, and in residue on vegetables and fruits

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 GalliumUse of Gallium

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 EffectsHealth Effects

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 EffectsEnvironmental Effects

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