what is the atomicity of phosphorous?and valency?

Atomicity is the number of atoms of an element present in one molecule of that element. For example, there are 2 atoms of hydrogen present in H2 molecule. So its atomicity is 2.

The number of atoms present in a molecule of phosphorus are 4. So the atomicity of phosphorus is 4. Also, phosphorus shows two valencies - 3 and 5. For example, in P2O3, phosphorus shows a valency of 3, while in PCl5, it shows a valency of 5. 

  • 11


Atomicity of phosphorus is 4,as it has 4 atoms present in it.

The valency of Phosporus is 3 and 5 because it has variable valency.

The valency is determined by how many electrons the atom is using to bond with another atom to form a compound. The electrons present in the outermost orbit are generally involved in bond formation. The electronic configuration in terms of s, p, d and f shells is 1s2, 2s2, 2p6, 3s2, 3p3. The 3 electrons present in 3p sub shell can easily take part in bond formation. Also, it can very efficiently involve the 2 electrons present in 3s sub shell.
That is why it shows variable valencies i.e., 3 and 5.
Hope, this piece of information helps you.
Best wishes!
  • 8
What are you looking for?