Question

Which of the following statements concerning lanthanide elements is false?

• A. Lanthanides are separated from one another by ionexchange method.
• B. Ionic radii of trivalent lanthanides steadily increase with increase in the atomic number.
• C. All lanthanides are highly dense metals.
• D. More characteristic oxidation state of lanthanide elements is $+3$

Answer 1

Answer: (B)

The ionic radii of lanthanide elements decreases steadily with increase in atomic number due to lanthanoid contraction.