Chlorine has a valency of 1, 3, 5, or 7, depending on the specific compound it forms. Valency is the number of bonds an atom can form by either gaining, losing, or sharing electrons to achieve a stable electron configuration. Chlorine typically exhibits a valency of 1 when it gains one electron to achieve a stable, full outer electron shell. However, in certain compounds like chlorine trifluoride (ClF₃) or perchloric acid (HClO₄), chlorine can exhibit valencies of 3, 5, or 7 by forming multiple bonds or accepting additional electrons to achieve a stable configuration in those specific molecular contexts.