d and f BLOCK ELEMENTS

What is the typical oxidation state for elements like Fe, Co, and Ni towards the end of the 3d series?

• +1 or +2
• +2 or +3
• +4 or +5
• +6 or +7

Which of the following best explains why Scandium(II) is virtually unknown?

• It is too large
• It readily loses 3 electrons to achieve a stable configuration
• It has high electronegativity
• It forms only covalent bonds

What is the oxidation state of Chromium in the dichromate ion (Cr₂O₇²⁻)?

• +3
• +4
• +5
• +6

Which of the following species represents the highest oxidation state mentioned for Manganese?

• Mn²⁺ in MnCl₂
• Mn³⁺ in MnF₃
• Mn⁴⁺ in MnO₂
• Mn⁷⁺ in MnO₄⁻

What is the main reason for the decrease in stability of higher oxidation states beyond Manganese in the 3d series?

• Increase in atomic size
• Decrease in nuclear charge
• Fewer orbitals available for electron sharing
• Increase in ionization energy