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Gallium

physical science Maturity 7-9 Next article →

Gallium is a fascinating chemical element with the symbol Ga. It has the atomic number 31. This metal is soft and silvery in its solid form.

6N Gallium sealed in vacuum ampoule
6N Gallium sealed in vacuum ampoule

When it melts, it turns a silvery white color. It is a very special metal because it can change states easily. Most metals stay solid at room temperature, but gallium is different. It is one of only four non-radioactive metals that are liquid near room temperature. These other metals are caesium, rubidium, and mercury.

Liquid gallium pouring
Liquid gallium pouring

One of the most amazing things about gallium is its melting point. The melting point is about 29.76 degrees Celsius. This is just above normal room temperature. It is also close to average summer daytime temperatures in many places. Because of this, gallium will melt if you hold it in your hand.

However, you must be careful when it freezes. When gallium changes from a liquid to a solid, its volume expands by 3.10%. This means it gets bigger as it freezes. If you store it in a tight container, the expanding metal might break the container.

Scientists first discovered this metal in 1875. A French chemist named Paul-Émile Lecoq de Boisbaudran found it in Paris, France.

Bauxite Jamaica 1984
Bauxite Jamaica 1984

Gallium does not exist as a pure metal on its own in nature. Instead, it is found in tiny amounts inside other rocks. You can find it in zinc ores like sphalerite. It is also found in bauxite. People can get the metal by a process called smelting. This is how we extract the metal from the rocks.

Gallium is very important for the technology we use every day. It is mostly used in electronics. It helps make semiconductors, which are parts that control electricity. For example, gallium arsenide is used in microwave circuits and high-speed circuits.

Blue LED and Reflection
Blue LED and Reflection

Other compounds like gallium nitride help create blue and violet light-emitting diodes, or LEDs. It is even used to make jewelry by making artificial garnet. Gallium can also be mixed with other metals to make alloys. One alloy is called galinstan. It is made of gallium, indium, and tin.

Galinstan on glass
Galinstan on glass

This special alloy, galinstan, is a great way to use gallium safely. It stays liquid even at very low temperatures. Because of this, it is used in thermometers. It is a non-toxic and environmentally friendly choice. This makes it a much safer alternative to mercury. Mercury is very toxic to living things. Gallium is much easier to handle because it is not highly toxic. It can also be used to make brilliant mirrors when painted onto glass.

Gallium alloy 3D prints (26519727708)
Gallium alloy 3D prints (26519727708)

You might see its effects in the bright lights of your gadgets.

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🖼️ Images & Media (8)
File:Gallium kristallisiert.JPG
Gallium kristallisiert.JPG
File:Liquid gallium pouring.png
Liquid gallium pouring.png
Gallium drops.ogv
File:6N Gallium sealed in vacuum ampoule.jpg
6N Gallium sealed in vacuum ampoule.jpg
File:Bauxite Jamaica 1984.jpg
Bauxite Jamaica 1984.jpg
File:Blue LED and Reflection.jpg
Blue LED and Reflection.jpg
File:Galinstan on glass.jpg
Galinstan on glass.jpg
File:Gallium alloy 3D prints (26519727708).jpg
Gallium alloy 3D prints (26519727708).jpg
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