To determine the electron configuration of the \( P^{3-} \) ion, let's go through the steps in detail:
1. Identify the atomic number of phosphorus (P):
Phosphorus has an atomic number of 15, meaning that a neutral phosphorus atom has 15 electrons.
2. Determine the electron configuration of a neutral phosphorus atom:
The electron configuration of a neutral phosphorus atom with 15 electrons is written as:
[tex]\[
1s^2 2s^2 2p^6 3s^2 3p^3
\][/tex]
This can also be abbreviated using the noble gas notation as:
[tex]\[
[Ne] 3s^2 3p^3
\][/tex]
Here, \([Ne]\) represents the electron configuration of neon, which accounts for the first 10 electrons.
3. Determine the effect of the \(3-\) charge:
The \(3-\) charge indicates that the phosphorus ion has gained 3 additional electrons. Adding these 3 extra electrons to the neutral phosphorus atom, we need to place them in the next available orbitals.
4. Calculate the total number of electrons in \(P^{3-}\):
The neutral phosphorus atom has 15 electrons. Adding 3 more electrons results in a total of 18 electrons for the \(P^{3-}\) ion.
5. Write the electron configuration for 18 electrons:
The electron configuration for 18 electrons corresponds to that of the argon atom, which completes the 3p orbital.
So, the electron configuration becomes:
[tex]\[
1s^2 2s^2 2p^6 3s^2 3p^6
\][/tex]
This can also be expressed using noble gas notation as:
[tex]\[
[Ar] 3s^2 3p^6
\][/tex]
Here, \([Ar]\) represents the electron configuration for argon, which includes 18 electrons.
Therefore, the electron configuration of the [tex]\( P^{3-} \)[/tex] ion is [tex]\(\boxed{[Ar] 3s^2 3p^6}\)[/tex].
