Hydrogen has one valence electron. This is because hydrogen has only one electron in total, which occupies its outermost and only shell (1s orbital). Being in Group 1 of the periodic table, hydrogen has one electron in its valence shell

. When hydrogen forms a bond, such as in H₂, it shares this single valence electron with another hydrogen atom, effectively filling its outer shell with two electrons through covalent bonding, achieving a stable electron configuration similar to helium