Biology Question about Valence of Phosphorous...

[xilc]

I was just reading through this in my bio book, and it was very unspecific... If you read it it claims that the valence of Phosphorus has a valence of 3, due to 3 unpaired valance electrons in the Valence shell... But in some molecules involving phosphorous, it can have 3 single bonds and a double bond.... and thus, have a valance of 5... how is this possible? 😕

---

Members don't see this ad.

 

[candav]

It's been so long since I've done anything related to this, but if I remember correctly: consider that the valence configuration of P is 3s^2 3p^3. A stable ion can be formed by losing the three p-orbital electrons (P3+), or by losing the three p-orbital electrons as well as the two s-orbital electrons (P5+).

Hope this is correct...it has (thankfully) been years since I've had to worry about this.

 

[xilc]

It's been so long since I've done anything related to this, but if I remember correctly: consider that the valence configuration of P is 3s^2 3p^3. A stable ion can be formed by losing the three p-orbital electrons (P3+), or by losing the three p-orbital electrons as well as the two s-orbital electrons (P5+).

Hope this is correct...it has (thankfully) been years since I've had to worry about this.

I honestly couldn't read half of that haha... but if I'm going into med school will I even need this? haha if not I won't worry too much on it... 😕

 

[ReptarBar]

your book is weird. i've never heard anyone refer to the "valence" of atoms...you just state how many valence electrons the atoms have...hydrogen 1...oxygen 6...phosphorus 5...etc.

and yea, phosphorus is weird. just remember that it usually has 3 bonds or 5 bonds. both of them give phosphorus a formal charge of zero (3 bonds and 2 unpaired electrons, or 5 bonds) even though it ends up with 10 electrons in the outer shell (which is weird for elements that don't have D or F orbitals).

 

[Ontology]

Yeah, I think I'm using the same book as you. Phosphorus, for all intended purposes, has a valence of three. However, when it bonds with some molecules, it creates bonds that would lead you to think it has a valence of 5 but it actually has a valence of three.

 

[idontcaureuknow]

I was just reading through this in my bio book, and it was very unspecific... If you read it it claims that the valence of Phosphorus has a valence of 3, due to 3 unpaired valance electrons in the Valence shell... But in some molecules involving phosphorous, it can have 3 single bonds and a double bond.... and thus, have a valance of 5... how is this possible? 😕

Phosphorous is in row three of the periodic table, which actually has d orbitals in the valence energy levels (also, unoccupied). Thus phosphorous can have an "expanded" octet utilizing the d orbitals in the chemical bonds.

In terms of hybrid orbitals, instead of only being sp^3, it is now sp^3 d.

That is the basic explanation of how it works.

 

[sector9]

SDN is not for homework help. Closing.