# How many protons in the P_4 molecule?

Jul 16, 2017

#### Answer:

Well, the ${P}_{4}$ molecule has $4 \times 15$ $\text{NUCULAR PROTONS}$

#### Explanation:

And if has 60 such unit positive charges, it must necessarily have 60 corresponding electronic charges, in the form of 60 electrons, whizzing about the nuclear core.

And an isolated phosphorus atom MUST have 15 electrons, to match the atomic number $Z = 15$. For $P C {l}_{5}$, given that phosphorus is conceived to be ${P}^{+ V}$, the central phosphorus atom has 10 electrons, and the chloride ligands each have a formal negative charge.....(why?).

And a ${P}^{3 -}$ has a full valence electronic shell with 18 electrons.....and we have already accounted ${P}^{5 +}$ in $P C {l}_{5}$.

And to assign charges and electron numbers, all I am doing is noting the nuclear charge, i.e. $Z = 15$, and adding or subtracting electrons to make up the quoted charge. Why can't I add protons to the nuclear core of the phosphorus atoms to modify the charge?