Question

Why the valency of iron is 3 even though iron needs 4 electrons to fill 3d orbitals

Answer 1

Answer:

When iron loses the 2 4s electrons, it attains a valency of +2. Sometimes, iron will also lose one of the paired electrons from 3d orbital, leaving the entire 3d orbital filled with unpaired electrons (which provides a more stable configuration). In this case, its valency will be +3. Hope this helps you.