Isotopes of Arsenic

The atomic mass of Arsenic listed on the periodic table is 74.92 u. Arsenic has over 33 different isotopes, ranging from 60 to 92 in atomic mass. However, only one of these isotopes is stable, which is ⁷⁵As. Therefore, Arsenic is a monoisotpoic element. Like the rest of the nitrogen group, Arsenic has five valence electrons. In group five, Arsenic is most closely related to antimony, both being metalloids. Since nitrogen and phosphorus are non-metal, they share very little commonalities with arsenic and antimony. As with bismuth being a P-block metal, they too share very little similarities.