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G A L L I U M. Group13 Siti Rohmatikah (10503046) Rasminda Senovita (10503047) Nurrahmi H (10503048) Dani Setiawan (10503049). Overview of Gallium. Origin of name: L. Gallia, France Latin, gallus , a translation of Lecoq, a cock History:
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G A L L I U M Group13 Siti Rohmatikah (10503046) Rasminda Senovita (10503047) Nurrahmi H (10503048) Dani Setiawan (10503049)
Overview 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 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 • 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 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 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 & 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 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 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 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