Question 3, HW 5&6

[Sophia Olender 2J]

The question asks you to draw the Lewis structures of the nitrite, nitrate, phosphite, and phosphate ions. Draw the structures that minimize formal charges, and be sure to include the appropriate formal charge and lone-pair electrons.

For the phosphate ion, why can the phosphorous atom share 10 electrons? I thought it can only hold 8 electrons for an octet. I understand that it has 5 valence electrons, so it can have 5 bond lines, but I'm confused why this happens if atoms tend to try to achieve an octet.

[Kaya L]

It is possible for a central atom such as P in this case to have more or less than 8 valence electrons because electrons are never in a fixed position. This usually means the structure is not in formal charge though.

[Benjamin Nguyen 1J]

Phosphorus can break the octet rule because it is in the 3rd period where n = 3, meaning it has the empty 3d orbital to put more electrons.

[KatieWu 1E]

Phosphorus atom can share 10 electrons because it's in the 3rd row, which has a d orbital, giving it an extra 2 electrons to work with.

[Crystal Ma 2J]

Hi,
This corresponds with what we went over in class today, which is that since phosphorus is in the 3rd period, it has a d orbital, which allows for additional electrons to be accommodated. This goes for atoms in the 3rd period and beyond!