Boron Family

Made by;

Ethan Borochaner, Eric Mitchell, Kevin Lee, and Pascal Portney

History and Discovery

• Boron - It comes from the Persian and Arabic words for borax. The compounds were known in ancient times but were isolated in 1808 by Gay-Lussac and Thenard and independently by Sir Humphrey Davy

• Aluminum - Named from the Latin Alum, and its existence was proposed by Lavoisier in 1787. Named by Davy in 1807 and isolated by Orsted in 1825.

History and Discovery• Gallium - originally predicted by Mendeleev in 1871. It

was isolated from Paul-Emile Lecoq de Boisbaudran in 1875 and named after Gallia, Latin for France.

• Thallium - discovered by Sir William Crookes in 1861. It was identified by its positive bright green line in the spectrum like its Greek name Thallios for green twig.

• Indium - named from Latin Indicum for indigo and discovered by Reich and Richterin in 1863.

Common Applications

• Indium• The first large-scale application for Indium was as a

coating for bearing in high-performance aircraft engines during World War II.

• Gallium• Since gallium wets glass or porcelain, Gallium can be

used to create brilliant mirrors • Gallium is used in some high temperature

thermometers • Gallium Nitrate is used in some treatments for arthritis

Common Applications• Aluminum

• important in virtually all segments of the world economy

• nearly all modern mirrors are made using a thin coating of Aluminum

• commonly used silvering agent in paint

• Thallium• there are no uses for metallic Thallium because

when mixed with some other substances, it creates a powdery black substance

• was once used as a rat and ant poison

Common Applications

• Boron• Boron is an essential plant micronutrient, playing a

key role in plant fertilization; also in the building of cell wall structures

• Boric Acid also traditionally used as an insecticide• Borax is sometimes found in laundry detergent

Common Reactions

Boron

AluminumGallium

IndiumThallium

Aluminum Reaction

http://www.youtube.com/watch?v=R6bBs2D0cpA&feature=related

Physical Properties

BoronMelting Point: 2348 KBoiling Point: 4273 KDensity: 2.37 grams per cubic centimeterElectronegativity: 2.04Atomic Radius: 85

AluminumMelting Point: 933.437 K Boiling Point: 2792 KDensity: 2.70 grams per cubic centimeterElectronegativity: 1.61Atomic Radius: 125

Physical Properties

GalliumMelting Point: 302.91 K Boiling Point: 2477 KDensity: 5.91 grams per cubic centimeterElectronegativity: 1.81Atomic Radius: 135

IndiumMelting Point: 429.75 K Boiling Point: 2345 KDensity: 7.31 grams per cubic centimeterElectronegativity: 1.78Atomic Radius: 155

Physical Properties

ThalliumMelting Point: 577 KBoiling Point: 1746 KDensity: 11.8 grams per cubic centimeterElectronegativity: 1.83Atomic Radius: 190

Patterns Among Properties

For the Boron family• The ionization energy decreases as you go down the

group.• Valence electrons: 3 electrons in their outer level• The density increases as you go down the group• The Atomic Radius increases as you go down the group• The Melting points for the elements have no pattern, yet

the boiling points decrease as you go down the Boron Family