Here's how to determine the total valence electrons in PCl₃:

* Phosphorus (P): Phosphorus is in Group 15 (or 5A) of the periodic table, so it has 5 valence electrons.

* Chlorine (Cl): Chlorine is in Group 17 (or 7A) of the periodic table, so it has 7 valence electrons. Since there are three chlorine atoms, we multiply by 3: 7 * 3 = 21 valence electrons.

Total: 5 (P) + 21 (Cl) = 26 valence electrons