Phosphorus Example in Class

[Alexis DeHorta 2A]

I was wondering if someone could explain to me how we created the phosphorus structure today for our chemistry lecture. I know that Phosphorus has 5 electrons, meaning it can make 3 bonds. However, in the structure we made in class, the example showed Phosphorus having 5 bonds with Chlorine. It was example 7, phosphorus pentachloride: PCl5

[Neelaj Das 3I]

Phosphorus does indeed have 5 valence electrons and even though it has one lone pair from the 3s^2 orbital, this lone pair can participate in bonding which is why phosphorus can form 5 bonds. Additionally, due to the fact that phosphorus is in period 3, it is capable of having an expanded octet which is why in the molecule PCl5, phosphorus is capable of having 10 valence electrons.