The number of valence electrons in gallium (Ga) is 3. Gallium is a chemical element with the atomic number 31 and the chemical symbol Ga. It is a silvery white metal that is soft and malleable. Gallium has three valence electrons in its outermost electron shell, which means that it can easily lose or gain electrons in chemical reactions. This makes gallium a good conductor of electricity and heat, and it is also used in various electronic and semiconductor devices.