d and f BLOCK ELEMENTS

What is the primary cause attributed to the lanthanoid contraction?

• The imperfect shielding of one 4f electron by another within the same sub-shell
• The perfect shielding of 4f electrons
• The increase in the number of 5d electrons
• The decrease in nuclear charge

What is the general electronic configuration for the most stable tripositive (Ln³⁺) ions of Lanthanoids?

• 4fⁿ (n=1 to 14)
• 5dⁿ (n=1 to 10)
• 6s²4fⁿ
• 5s²5p⁶

What is the common outer electronic configuration for Lanthanoid atoms?

• 6s²
• 5d¹
• 4f¹⁴
• 6p²

What is the oxidation state of iodine in the iodate ion (IO3^-)?

• +1
• +3
• +5
• +7

What is the oxidation state of nitrogen in the nitrate ion (NO3^-)?

• +3
• +4
• +5
• +7