No. That's not right.
Iron has the electronic structure:
The 4s electrons are in the highest energy level so can be regarded as the valence electrons.
When these are lost in chemical reactions the
The +3 state can also be formed which is:
This gives the
This is not right.
A valence electron for a transition metal is defined as an electron that resides outside a noble-gas core.
The electron configuration of iron is
That does not mean that Fe will use all eight of its valence electrons to form compounds.
Fe can also lose a
These are the most common oxidation states of Fe.
In some compounds, Fe has oxidation states of +4, and +6, but they are uncommon.
The number of valence electrons in a transition metal that will actually participate in a chemical reaction is hard to predict.
So, the concept of valence electrons is less useful for a transition metal than for a main group element.
Transition metal chemists use words like "d-electron count" and the "18-electron rule", but they are more advanced concepts.