How many electrons are in the valence shell of Gallium (Ga)?

Gallium (Ga) is located in Group 13 of the periodic table. The electron configuration of gallium is [Ar] 3d10 4s2 4p1. To find the number of valence electrons, we need to consider the electrons in the outermost shell, which includes the highest principal energy level (n).

For gallium, the outermost shell is the fourth energy level (n=4), which contains two electrons from the 4s subshell and one electron from the 4p subshell. Adding these together gives a total of three valence electrons in the 4s and 4p orbitals.

Thus, gallium has three electrons in its valence shell, aligning with its position in Group 13 and confirming that the number of valence electrons is accurately represented by the selected option.