The valence electrons that take part in forming bonds are called bonding pairs of electrons, whereas those that do not form bonds are called lone pairs of electrons. The Lewis structure of any molecule helps understand the arrangement of atoms in the molecule, its bond formation, and the valence electrons participating in forming bonds. Total number of valence electrons in POCl3 – Valence electrons of phosphorus + valence electrons of Oxygen + valence electrons of chlorine These valence electrons participate in bond formation.įor finding out the total number of valence electrons for POCl3, we find the valence electrons of all the atoms.Ĭhlorine has seven valence electrons, but as there are three chlorine atoms, we will multiply the number by 3. The electrons that are present in the outer shell are called valence electrons. To determine the Lewis structure of any molecule, we first need to know the total number of valence electrons for the molecule.
