The P4 molecule, also known as white phosphorus, consists of four phosphorus atoms arranged in a tetrahedral shape. To draw its Lewis structure, we start by determining the total number of valence electrons. Each phosphorus atom has five valence electrons, so for P4, we have:
4 × 5 = 20 valence electrons.
Next, we arrange the four phosphorus atoms in a tetrahedral configuration. Each phosphorus atom will form single bonds with the other three phosphorus atoms. This means we will use 6 electrons (3 bonds × 2 electrons per bond) for the bonding.
After forming the three single bonds, we have:
20 – 6 = 14 electrons remaining.
Since each phosphorus atom can form a total of 8 electrons in its valence shell, we distribute the remaining electrons to satisfy the octet rule. In the case of P4, each phosphorus atom ends up with a lone pair of electrons after forming single bonds with the others.
The resulting Lewis structure is:
In this structure, each phosphorus is connected to three others and has one lone pair. This arrangement leads to a stable molecule with a tetrahedral geometry.