Nitrogen Family
Group 15 elements show varied oxidation states from -3 to +5.
Group 15 elements show varied oxidation states from -3 to +5.
Group 15 comprises nitrogen, phosphorus, arsenic, antimony and bismuth, each with five valence electrons in the ns2 np3 configuration. Nitrogen forms an extremely strong triple bond, with a bond energy of about 945 kJ/mol, so N2 is very unreactive at normal temperatures. Down the group the elements become more metallic, and the +5 state becomes less stable relative to +3 because of the inert pair effect. Oxidation states range from -3 in ammonia to +5 in nitric acid. Nitrogen and phosphorus are essential for life, forming parts of proteins, nucleic acids and ATP.
Key ideas: Group 15 ns2 np3: N, P, As, Sb, Bi. Nonmetallic character falls down the group: N and P nonmetals, As and Sb metalloids, Bi metal. N2 has a very strong triple bond (945 kJ per mol), so it is inert at room temperature. P forms five bonds using d orbitals (PCl5), while N cannot. Basic strength of hydrides falls: NH3 greater than PH3 greater than AsH3. Bond angle falls from 107 to 93 degrees.
Common mistakes and connections: Students expect nitrogen to form NCl5 or N2 to be reactive because N is electronegative; strong triple bond makes it inert. Oxoacid trend: H3PO4 is not oxidizing while HNO3 is. Bi favors +3 due to the inert pair effect. Links to ammonia, nitric acid, fertilizers and VSEPR.
Electronegativity falls from N (3.0) down to P (2.2) in Group 15, matching the change from nonmetallic nitrogen toward metallic bismuth. The interactive lesson shows this as a live animation or chart.
In ammonia, NH3, nitrogen is -3, while in nitric acid, HNO3, it is +5.
Group 15 elements show varied oxidation states from -3 to +5.
Nitrogen Family is a beginner topic in Inorganic Chemistry. It needs no earlier chemistry lessons and is a good starting point.
Study these earlier topics in Inorganic Chemistry first: Glass, Carbon Oxides, Carbides.
The next topics in Inorganic Chemistry are Ammonia and Oxides of Nitrogen.
Yes. The interactive lesson includes a self-check question on Nitrogen Family, and the Inorganic Chemistry quiz draws on every topic in this area.
Nitrogen Family is topic 31 of 113 in Inorganic Chemistry.