Nitrogen Family of Elements

Nitrogen Family - Element Group 15

Move down the periodic table from nitrogen to find the members of the nitrogen family.
Move down the periodic table from nitrogen to find the members of the nitrogen family. dem10 / Getty Images

The nitrogen family is element group 15 of the periodic table. Nitrogen family elements share a similar electron configuration pattern and follow predictable trends in their chemical properties.

Also Known As: Elements belonging to this group are also known as pnictogens, at term derived from the Greek word pnigein, which means "to choke". This refers to the choking property of nitrogen gas (as opposed to air, which contains oxygen as well as nitrogen). One way of remembering the identity of the pnictogen group is to remember the word starts with the symbols of two of its elements (P for phosphorus and N for nitrogen). The element family may also be termed pentels, which refers both to the elements formerly belonging to element group V and their characteristic of having 5 valence electrons.

List of Elements in the Nitrogen Family

The nitrogen family consists of five elements, which start with nitrogen on the periodic table and move down the group or column:

  • nitrogen
  • phosphorus
  • arsenic
  • antimony
  • bismuth

It's likely element 115, moscovium, also exhibits traits of the nitrogen family.

Nitrogen Family Facts

Here are some facts about the nitrogen family:

  • Nitrogen family elements consists of atoms having 5 electrons in their outer energy level. Two of the electrons are in the s subshell, with 3 unpaired electrons in the ​p subshell.
  • As you move down the nitrogen family: atomic radius increases, ionic radius increases, ionization energy decreases, and electronegativity decreases.
  • Nitrogen family elements often form covalent compounds, usually with the oxidation numbers +3 or +5.
  • Nitrogen and phosphorus are nonmetals. Arsenic and antimony are metalloids. Bismuth is a metal.
  • Except for nitrogen, the elements are solid at room temperature.
  • Element density increases moving down the family.
  • Except for nitrogen and bismuth, the elements exist in two or more allotropic forms.
  • Nitrogen family elements display a wide range of physical and chemical properties. Their compounds may be transparent, either diamagnetic or paramagnetic at room temperature, and may conduct electricity when heated. Because the atoms form double or triple bonds, the compounds tend to be stable and potentially toxic.

Element facts include crystal data for the most common allotropes and data for white phosphorus.

Uses of Nitrogen Family Elements

  • Two of the elements, nitrogen and phosphorus, are essential for life.
  • Most of the Earth's atmosphere consists of nitrogen gas, N2. Diatomic pnictogen molecules like this may be called pnictides. Because of their valence, pnictide atoms are connected by a covalent triple bond.
  • Phosphorus is used in matches, fireworks, and fertilizer. It's also used to make phosphoric acid.
  • Arsenic is toxic. It has been used as a poison and as a rodenticide.
  • Antimony finds use in alloys.
  • Bismuth is used in medications, paint, and as a catalyst.

Nitrogen Family - Group 15 - Element Properties

N P As Sb Bi
melting point (°C) -209.86 44.1 817 (27 atm) 630.5 271.3
boiling point (°C) -195.8 280 613 (sublimes) 1750 1560
density (g/cm3) 1.25 x 10-3 1.82 5.727 6.684 9.80
ionization energy (kJ/mol) 1402 1012 947 834 703
atomic radius (pm) 75 110 120 140 150
ionic radius (pm) 146 (N3-) 212 (P3-) -- 76 (Sb3+) 103 (Bi3+)
usual oxidation number -3, +3, +5 -3, +3, +5 +3, +5 +3, +5 +3
hardness (Mohs) none (gas) -- 3.5 3.0 2.25
crystal structure cubic (solid) cubic rhombohedral hcp rhombohedral

Reference: Modern Chemistry (South Carolina). Holt, Rinehart and Winston. Harcourt Education (2009).

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Your Citation
Helmenstine, Anne Marie, Ph.D. "Nitrogen Family of Elements." ThoughtCo, Apr. 5, 2023, Helmenstine, Anne Marie, Ph.D. (2023, April 5). Nitrogen Family of Elements. Retrieved from Helmenstine, Anne Marie, Ph.D. "Nitrogen Family of Elements." ThoughtCo. (accessed June 7, 2023).