Pniktogenen

Pniktogenen, also known as the pnictogens, are the elements in Group 15 of the periodic table, commonly referred to as the nitrogen group. The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and the synthetic element moscovium (Mc). They share an outer-shell electron configuration of ns2 np3 and typically exhibit oxidation states from -3 to +5, with lighter members showing a broader range and heavier ones tending toward +3 and +5.

Across the group, electronegativity decreases and metallic character increases. Nitrogen is a nonmetal, phosphorus is a nonmetal with several allotropes (white, red, black), arsenic and antimony are metalloids, and bismuth and moscovium are metals (with moscovium being synthetic and extremely short-lived, thus lacking practical applications). The pnictogens form hydrides such as ammonia (NH3), phosphine (PH3), arsine (AsH3), and, to a lesser extent, stibine (SbH3); bismuthine (BiH3) is unstable. They also form oxides ranging from nitrous oxides (NO, NO2) and dinitrogen pentoxide (N2O5) to P4O10, As2O3, Sb2O3, and Bi2O3.

Occurrence and applications: nitrogen makes up about 78% of Earth's atmosphere; phosphorus is obtained mainly from phosphate rocks; arsenic, antimony, and bismuth occur in various mineral deposits. Phosphorus is central to fertilizers and biology; nitrogen is essential for life; arsenic compounds are toxic and have historical medicinal and pesticidal uses; antimony and bismuth find uses in alloys, flame retardants, and medicines. Moscovium has no practical applications outside research due to its short half-life.

Etymology: the name pnictogen derives from Greek pnigein, “to choke,” referring to the choking fumes of some compounds; the group is also called the nitrogen family.