What is the atomic number of Gallium?

The atomic number for gallium is 31. Gallium was discovered (1875) by French chemist Paul-Émile Lecoq de Boisbaudran, who observed its principal spectral lines while examining material separated from zinc blende. Soon afterward he isolated the metal and studied its properties, which coincided with those that Russian chemist Dmitry Ivanovich Mendeleyev had predicted a few years earlier for eka-aluminum, the then-undiscovered element lying between aluminum and indium in his periodic table.

Though widely distributed at Earth’s surface, gallium does not occur free or concentrated in independent minerals, except for gallite, CuGaS2, rare and economically insignificant. It is extracted as a by-product from zinc blende, iron pyrites, bauxite, and germanite.