how to know whether an element have vacant d orbital or not?
Answers
Answer:
write the electronic configuration to know whether the element have vacant d orbital or not.
Answer:
Hydrogen for example (H®1s1) has only one unpaired electron and shows a covalency of one.
N atom (N→2s22px12py12pz1) has three unpaired electrons and shows a covalency of three.
O atom (O→2s22px22py12pz1) has two unpaired electrons and shows a covalency of two.
F atom (F→2s22px22py22pz1) has one unpaired electrons and shows a covalency of one.
If you observe these elements given above have only s and p orbitals in their valence shells and do not contain vacant d orbitals.
However elements like P, S, and Cl contain vacant d-orbitals and show different values of covalency in different covalent compounds.
It is called variable covalency and is due to the presence of vacant d-orbitals in the valency shell of these elements.
Some examples of elements showing different covalencies in compounds.
Elements
Different covalencies
Examples of Compounds
Halogens(Other than fluorine)
1
3
5
7
ICl
ICl3
ICl5
ICl7
Sulphur
2
4
6
SCl2
SF4
SF6
Phosphorus
3
5
PCl3
PCl5
Variable covalency of phosphorus of P atom (3,5)
P in Ground state : 3s2 3px1 3py1 3pz1
Phosphorus in its excited state: 3s1 3px1 3py1 3pz13d1