An element is a pure substance made of one type of atom, unable to be broken down by ordinary chemical means. Each element is uniquely identified by its atomic number, a fundamental characteristic that distinguishes it from others and dictates its place in the chemical world.
Gallium’s Atomic Number
The atomic number for gallium is 31. This number indicates that every gallium atom contains 31 protons. Gallium is represented by the chemical symbol “Ga” on the periodic table. Its atomic number of 31 places it directly after zinc (atomic number 30) and before germanium (atomic number 32) in the periodic table’s fourth period.
Why Atomic Numbers Matter
The atomic number defines an element’s identity and governs its chemical properties. This number determines the arrangement of electrons around the nucleus, which dictates how an atom interacts with others. For gallium, its atomic number of 31 places it in Group 13 of the periodic table, alongside elements like aluminum and indium. This placement explains its tendency to form compounds where it loses three electrons, influencing its reactivity and bonding.
Gallium’s Distinctive Characteristics and Uses
Gallium possesses several distinctive physical and chemical properties that make it valuable in various applications. A notable characteristic is its unusually low melting point of 29.76 °C (85.57 °F), which means it can melt when held in a human hand. This property makes it one of the few metals that can exist as a liquid near room temperature. Gallium also exhibits a high boiling point, creating a wide liquid range, making it suitable for high-temperature thermometers.
Its properties make it suitable for advanced technological applications. Gallium is widely used in the semiconductor industry, particularly in compounds like gallium arsenide (GaAs). Gallium arsenide is a key material for integrated circuits, especially in high-frequency and high-power applications, due to its faster electron conductivity than silicon. Gallium nitride (GaN) and gallium phosphide (GaP) are foundational materials for light-emitting diodes (LEDs) and laser diodes, enabling efficient lighting and optical communication.
The Discovery of Gallium
Russian chemist Dmitri Mendeleev predicted gallium’s existence and properties in 1871, four years before its discovery. He referred to it as “eka-aluminum” based on his periodic law, foreseeing the characteristics of undiscovered elements. Mendeleev accurately predicted its atomic weight, density, and chemical behavior.
Gallium was isolated and identified in 1875 by French chemist Paul-Émile Lecoq de Boisbaudran. He discovered the element using spectroscopic analysis of a zinc blende mineral sample from the Pyrenees, confirming Mendeleev’s predictions.