Electronic Configuration - Group 15 Elements

Group 15 elements in the modern periodic table are known as the pnictogens which means suffocation in Greek language. This group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi). The first two elements of this group are non-metallic in nature, arsenic and antimony are metalloids and bismuth is a metal.

Electronic configuration is the arrangement of electrons of an element in the orbital shells and sub-shells. Before we draw the electron diagram of an element we should understand the basic rules associated with writing the electronic configuration of an element. The three basic rules which have to be considered are:

  • Pauli’s exclusion principle

  • Hund’s rule

  • Aufbau’s principle

The lowest energy level should be filled first and then we should move on to fill the higher energy levels. Pauli’s exclusion principle states that no two electrons of an atom should possess the same quantum number (n, l, m, s). According to Hund’s rule, when electrons are distributed among the similar energy orbitals, initially one electron is distributed among each of the orbitals and then pairing of electrons starts.

In other words pairing of electrons in an orbital starts only when all the orbitals are occupied with a single electron. As per Aufbau’s principle, electrons are first distributed among lower energy levels and then moved on to higher energy levels. Electronic configuration of all the elements of the modern periodic table can be written using these rules. Electronic configuration of nitrogen family is shown below:

Period Element Symbol Atomic Number Electronic Configuration
2 Nitrogen N 7 [He]2s2p3
3 Phosphorus P 15 [Ne]3s3p3
4 Arsenic As 33 [Ar]3d10 4s4p3
5 Antimony Sb 51 [Kr]4d10 5s5p3
6 Bismuth Bi 83 [Xe]4f14 5d10 6s6p3

The group 15 elements consist of five valence electrons. Due to this the elements can either lose five electrons or gain three electrons in order to attain the stable configuration. The general electronic configuration of nitrogen family is ns2np3.