d and f BLOCK ELEMENTS

Why is the +2 oxidation state common for transition metals like Fe, Co, and Ni?

• It achieves a noble gas configuration
• It involves losing primarily the ns electrons
• It is the highest possible state
• It requires the least energy overall

What is the oxidation state of Iron in the complex ion [Fe(CN)₆]³⁻?

• +1
• +2
• +3
• +4

Which element among Sc, Ti, V, Cr is least likely to exhibit multiple oxidation states?

• Titanium
• Vanadium
• Chromium
• Scandium

In the compound K₂Cr₂O₇ (potassium dichromate), what is the oxidation state of Chromium?

• +3
• +4
• +5
• +6

Which of the following best explains why elements in the middle of the 3d series show maximum oxidation states?

• They have the largest atomic size
• Highest nuclear charge
• Optimal number of d electrons for flexibility
• They are the most electronegative