Question

Question #18660

Answer 1

Phosphorus can have both a positive and a negative valency.

Explanation:

If phosphorus combines with a metallic element it has a negative valance. The phosphorus because it has a higher electron negativity than the metals will act as an oxidizer taking electron away from the positive metals. This creates a valance of -3

If phosphorus combines with a non metal element with a higher electron negativity than phosphorus it will have a positive valance.

When phosphorus combines with Oxygen to form an phosphate ion it has a charge of +5 `PO_3^-1` This is because Oxygen will act as the oxidizer taking the electrons away from the phosphorus.

Phosphorus can have either a positive valance or a negative valance depending on what other element it is combining with and the relative electron negativity of the other elements.

Answer 2

Phosphorus has neither a positive or negative valency.

Explanation:

Valency is the number of `"H"` atoms or `"Cl"` atoms that can form bonds to a particular element.

Thus, in `"PH"_3` and in `"PCl"_3` the valency of phosphorus is 3.

In `"PCl"_5` the valency of phosphorus is 5.