Gallium

5.91
69.723
[Ar] 3d104s24p1
69Ga
13
4
p
31
2, 8, 18, 3
578.845
Ga
5.91
29.7646°C, 85.5763°F, 302.9146 K
2229°C, 4044°F, 2502 K
Paul-Émile Lecoq de Boisbaudran
1875
7440-55-3
4514603
More Information
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Uses and Properties

Image Explanation

Gallium undergoes a melting process when placed on the palm because of its exceptionally low melting point, and the heat from our hand is sufficient to effortlessly transform this metal into a liquid state.

Appearance

Gallium is a soft, silvery-white metal, similar to aluminium.

Uses



Gallium: A Versatile Metal with Surprising Applications














Gallium, with its atomic number 31 and symbol Ga, is not a metal that immediately comes to mind when we think about common elements. Yet, this unassuming metal has found its way into various niche applications across several industries. Gallium's unique properties, including its low melting point and remarkable electrical conductivity, make it an intriguing element for specialized uses. In this article, we will explore the surprising and diverse applications of gallium, shedding light on its role in our modern world.

 

Semiconductor Industry


One of the most significant applications of gallium is in the semiconductor industry. Gallium-based semiconductors, such as gallium arsenide (GaAs) and gallium nitride (GaN), offer several advantages over traditional silicon. These compounds are used to create high-frequency electronic devices, such as microwave amplifiers, microwave transistors, and high-speed digital logic circuits.

Gallium nitride, in particular, is prized for its ability to operate at higher temperatures and frequencies, making it an essential component in the production of LEDs (light-emitting diodes) and high-power electronics. GaN-based transistors are used in power converters for efficient energy conversion.

 

Thermometers and Thermostats


Gallium's unique property of melting at a low temperature, approximately 29.76 degrees Celsius (85.57 degrees Fahrenheit), makes it an ideal candidate for applications in thermometers and thermostats. Gallium-in-glass thermometers, also known as Galinstan thermometers, offer high precision in measuring temperatures, especially in laboratory and industrial settings.

Gallium's low melting point allows these thermometers to measure temperatures in a range where other materials may not be suitable. They are a valuable tool in various scientific fields, including chemistry and physics.

 

Aerospace Industry


Gallium's use extends to the aerospace industry, where it plays a crucial role in aerospace applications, including satellites and space exploration. The reliability and efficiency of GaAs-based semiconductors are invaluable in the extreme conditions of space.

Additionally, gallium compounds are used in propellants and rocket fuels. The energetic compound gallium/aluminum alloy is used as a component in solid rocket propellants, contributing to thrust and stability.

 

Solar Cells


Gallium's exceptional properties have earned it a place in the field of renewable energy. Gallium arsenide (GaAs) solar cells have demonstrated their efficiency in converting sunlight into electricity. These high-efficiency solar cells are used in space applications, such as solar panels on satellites and spacecraft.

While GaAs solar cells are more expensive to produce than traditional silicon solar cells, their remarkable efficiency makes them ideal for space missions, where reliability and energy generation are paramount.

 

Catalysis and Chemistry


Gallium compounds are used as catalysts in various chemical reactions. Gallium trichloride (GaCl3) is employed in Friedel-Crafts alkylation reactions, while gallium oxide (Ga2O3) is used as a catalyst in the production of synthetic rubber and in the purification of natural gas.

Gallium is also involved in organometallic chemistry, playing a role in the synthesis of certain organic compounds and pharmaceuticals.

 

Medical Imaging


Gallium-67, a radioactive isotope of gallium, is used in medical imaging to detect and diagnose various diseases, including cancer and inflammatory conditions. When administered intravenously, Gallium-67 collects in areas of increased metabolic activity, such as tumors or inflamed tissue.

This radiotracer emits gamma radiation, which can be detected using specialized imaging equipment, allowing physicians to pinpoint the location and extent of pathological changes in the body.

 

Metal Alloys


Gallium can be alloyed with other metals to create alloys with unique properties. One notable example is the creation of Gallium/Indium/Tin (GaInSn) alloys that remain in a liquid state over a wide range of temperatures. These eutectic alloys are used in applications like thermal interface materials (TIMs) to transfer heat efficiently between electronic components and heat sinks.

Gallium-based alloys are also utilized in low-temperature soldering and as coolants in advanced cooling systems for electronics and lasers.

 

Nuclear Reactors


Gallium's neutron-absorbing properties make it a valuable material in nuclear reactors. In the nuclear industry, gallium-based control rods are used to regulate the nuclear fission process in reactors. By adjusting the position of these rods, operators can control the rate of nuclear reactions and maintain reactor stability and safety.

 

Conclusion


Gallium, often overlooked in favor of more common metals, is a testament to the diverse and surprising applications that the periodic table offers. Its unique properties, from its low melting point to its remarkable electrical conductivity, have earned it a significant role in specialized fields and industries, ranging from semiconductors to aerospace.

As technology and science continue to advance, it is likely that gallium will find even more applications and contribute to innovative solutions in the years to come. Its presence in our modern world, though often discreet, underscores the incredible versatility and potential that even lesser-known elements possess.









History

Gallium, denoted by the symbol Ga and atomic number 31, is a metal with a history as intriguing as its unique properties. This unassuming element has made a remarkable journey through time, from its initial discovery to its vital role in modern technology. In this article, we delve into the enigmatic history of Gallium, tracing its path from obscurity to prominence.

 

The Elusive Quest for Predicted Elements


Gallium's story begins with the scientific curiosity and exploration of the 19th century. During this era, the periodic table was still taking shape, and chemists were working diligently to fill in the gaps, predicting the existence of elements that had not yet been discovered.

Dmitri Mendeleev, the renowned Russian chemist, had published the periodic table in 1869, organizing elements by their atomic number and properties. Mendeleev left gaps in the table for elements that he believed were yet to be found. These elements were later dubbed "eka-" followed by the name of the element above them, indicating their predicted properties based on their position in the table.

 

The Predicted Element: Eka-Aluminum


One of Mendeleev's predictions was for an element he named "eka-aluminum," located below aluminum in the periodic table. He calculated its properties, including its atomic mass and chemical behavior, with remarkable accuracy, even though it had not yet been isolated.

This prediction caught the attention of several chemists, including French chemist Paul-Émile Lecoq de Boisbaudran. Lecoq de Boisbaudran embarked on a mission to discover eka-aluminum and verify Mendeleev's predictions. His relentless efforts would ultimately lead to the discovery of Gallium.

 

Discovery of Gallium


In 1875, Lecoq de Boisbaudran successfully isolated the elusive element eka-aluminum from a sample of zinc blende, a mineral rich in zinc and sulfur. He observed that the element had a strikingly low melting point, around 30 degrees Celsius (86 degrees Fahrenheit), making it the first element ever discovered through the prediction of the periodic table.

Lecoq de Boisbaudran named the element Gallium after "Gallia," the Latin name for France, in honor of his home country. The name also highlighted the element's role in French scientific discovery.

 

Early Applications and Challenges


After its discovery, Gallium's unique properties made it a subject of scientific curiosity and experimentation. It was initially used in a few laboratory settings and for spectroscopic studies. However, Gallium's low melting point posed significant challenges for handling and storage, limiting its immediate practical applications.

 

The Role of Gallium in Semiconductors


Gallium's true potential began to emerge in the mid-20th century with the advent of the semiconductor industry. The semiconductor properties of Gallium arsenide (GaAs) were recognized, leading to its use in electronic devices such as transistors and diodes. GaAs-based semiconductors, with their high electron mobility, became crucial for high-frequency applications and communication devices.

Gallium's contributions to the development of efficient photovoltaic cells and lasers further solidified its importance in the technology sector. Gallium nitride (GaN) emerged as a vital material in the production of LEDs, power electronics, and other high-performance electronic components.

 

Gallium in Aerospace and Space Exploration


The aerospace industry also recognized the value of Gallium-based materials. GaAs solar cells became the standard for powering satellites and space probes, thanks to their high efficiency and durability in the harsh conditions of space. Gallium alloys found use in spacecraft structures and propellants.

 

Gallium in Everyday Life


While Gallium is not a household name, its impact is felt in various aspects of everyday life. Gallium thermometers, which exploit the metal's low melting point, are used for precision temperature measurement in scientific and industrial applications.

 

The Future of Gallium


Gallium's journey is far from over. As technology continues to advance, the applications and significance of Gallium are likely to expand further. Its unique properties, such as its low melting point and exceptional electrical conductivity, make it a vital material in fields like renewable energy, aerospace, and electronics.

 

Gallium's history is a testament to the power of scientific prediction, discovery, and innovation. From its initial identification as a predicted element, Gallium has evolved to become a pivotal component in the modern world. Its applications in semiconductors, aerospace, and beyond showcase the remarkable potential of elements that were once only theories on the periodic table.

As we continue to explore the possibilities of Gallium in cutting-edge technologies and scientific research, its legacy as a testament to human curiosity and ingenuity endures. Gallium stands as a testament to the remarkable journey from a predicted element to a transformative force in our technological landscape.

Atomic Data

Atomic Radiues, Non-bonded (A): 1.87
Electron Affinity (kJ mol-1): 41.49
Covalent Radiues (A): 1.23
Electronegativity (Pauling Scale): 1.81
Ionisation Energies (kJ mol-1) 1st 2nd 3rd 4th 5th 6th 7th 8th
578.845 1979.411 2964.589 6101.829 8298.7 10873.9 13594.8 16392.9

Oxidation States and Isotopes

Common oxidation states 1
Isotope Atomic Mass Natural Abundance Half Life Mode of Decay
69Ga 68.926 60.108 - -
71Ga 70.925 39.892 > 2.4 x 1026 y β-

Supply Risk

Relative Supply Risk: 7.6
Crustal Abundance (ppm): 16
Recycle Rate (%): <10
Production Conc.(%) : 54
Top 3 Producers:
1) China
2) Germany
3) Kazakhstan
Top 3 Reserve Holders:
Unknown
Substitutability: Medium
Political Stability of Top Producer: 24.1
Political Stability of Top Reserve Holder: Unknown

Pressure and Temperature Data

Specific Heat Capacity: 373
Shear Modulus: Unknown
Young Modulus: Unknown
Bulk Modulus: Unknown
Pressure 400k Pressure 600k Pressure 800k Pressure 1000k Pressure 1200k Pressure 1400k Pressure 1600k Pressure 1800k Pressure 2000k Pressure 2200k Pressure 2400k
- - 1.94 x 10-7 0.000565 0.114 4.98 84.4 - - - Unknown

Podcast

Transcript:

Gallium is a chemical element that belongs to the Group 13 of the periodic table. Gallium is an element that is a member of the Boron family. It is found in the periodic table between the transition metals zinc and germanium. There are several isotopes of the element. These isotopes have different atomic weights. The element is classified as a post-transition metal, meaning that it was produced after the formation of the four metalloids and transition metals. It is located between thallium and indium.

It is a metal with an atomic number of 31. This is an interesting element that is not classified as a non-metal. The atoms of gallium are arranged in an orthorhombic crystal structure. Typically, it is in the oxidation state of +3. Although it can be oxidized to a +1 state, it usually remains in a +3 state and its atoms are very similar to those of aluminum. Gallium is an important material for light-emitting diodes. Some of the lighter isotopes are radioactive and decay through positron emission. However, this element is toxic, when exposed to large amounts, it may cause throat irritation. Nevertheless, it can be useful as an alternative to mercury in dental alloys. Besides being a poor metal, gallium is a poor choice for transportation on flights because of its toxicity. Gallium is illegal to carry it on planes. It is relatively safe to handle. However, gallium can be toxic if heated too high.

This element was discovered by Paul-Emile Lecoq de Boisbaudran in 1875. While studying zinc, Lecoq noticed that there was a violet line in the atomic spectrum. He suspected the presence of an unknown element. After obtaining a small quantity of gallium from zinc ores, he reported the discovery to the French Academy of Sciences in December of that year.

He named it after his native country, France. He was able to obtain pure gallium from zinc ore through electrolysis. He proposed the name gallia for the new element.

This metallic element is found in the Earth's crust in a variety of minerals including sphalerite, diaspore, zinc blende, and bauxite. It is also a by-product in the production of aluminum and zinc. A small amount of gallium is found in flue dust from coal. Gallium is widely distributed at the surface of the Earth. In addition, Gallium is found in the passivation layer of aluminium. It is not widely produced in the United States, but is available in trace quantities. This element is extracted by electrolytic zinc. However, the element has attracted interest since the 1970s.

Gallium is a soft, silvery white metallic material that is liquid above room temperature. At room temperature, it is a solid, but it readily diffuses into cracks in some metals.

Gallium is classified as a semiconductor. It has a boiling point of 2204 degrees Celsius. The melting point is 2000 degrees Celsius, means 3600 Fahrenheit, which is lower than mercury and cesium. In the solid state, gallium has an orthorhombic crystalline structure. It breaks conchoidally, and can be cut with a knife. The atomic radius of gallium is surprisingly small, at 130 pm. However, the element has a higher ionization energy than aluminum.

The properties of Gallium are very similar to those of indium. Both have a strong affinity for other metals and they are very easy to alloy with. But gallium has an unusually large liquid range. This means that it can remain in its liquid form for a long time. It is also a toxic substance that can cause extreme loss of strength and ductility. Although this element is a brittle solid at cold temperatures, it is highly soluble in strong alkalis and acids, and it dissolves in liquids. Gallium easily transforms into alloys with most metals, and it can dissolve into the grain boundaries of some metals. In addition, gallium reacts with potassium hydroxide solutions to form gallate. The properties of gallium are well-known, although there are some aspects of its structure that have been less understood. When mixed with aluminum, gallium forms an alloy. When mixed with water, gallium forms a liquid that has a low vapour pressure. This makes it a good thermal interface material.

Gallium is non-toxic and can be handled without alarm. However, it can be corrosive. To avoid damaging glass and metal, you should wear gloves when handling it. It has a tendency to supercool below freezing. While it does not boil at room temperature, it can expand by 3.1 percent if frozen. If Gallium is heated to 4000 Fahrenheit, it will not dissolve, but it will vaporize.

The first use of gallium was in the design of metal alloys that were able to melt easily. However, there were some limitations. One of the most common applications is in the manufacture of data-centric networks. In addition, gallium nitride was found to be a critical material for light-emitting diodes. Gallium is used to stabilize crystal structures in nuclear bombs. This element is an essential component in many electronic devices and commercial items. Some of its important applications are in telecommunication and aerospace. Gallium is employed in creating high temperature thermometers. It can be used to create brilliant mirrors. As a semiconductor, gallium is used in the manufacture of Phosphide and Gallium Antimonide. This element is also an important component in efficient switching circuits. Moreover, Gallium is used in radiopharmaceuticals. A nuclear medicine test uses Ga67 to check for inflammation and infections. Gallium is used to make alloys with many other metals. Alloys with gallium are useful because of their optical properties. However, there is still a lot of research to be done in this area. Today, the element is used in optoelectronics. A large part of the world's consumption of this element comes from the manufacture of semiconductors.

References


  • W. M. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FL, 95th Edition, Internet Version 2015, accessed December 2014.

  • Tables of Physical & Chemical Constants, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed December 2014.

  • J. S. Coursey, D. J. Schwab, J. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopic Compositions (version 4.1), 2015, National Institute of Standards and Technology, Gaithersburg, MD, accessed November 2016.

  • T. L. Cottrell, The Strengths of Chemical Bonds, Butterworth, London, 1954.

  • John Emsley, Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, New York, 2nd Edition, 2011.

  • Thomas Jefferson National Accelerator Facility - Office of Science Education, It’s Elemental - The Periodic Table of Elements, accessed December 2014.