d and f BLOCK ELEMENTS

What is Gadolinium (Gd) notable for in terms of its electronic configuration and magnetism?

• It has a filled 4f subshell and is diamagnetic
• It has no 4f electrons and is weakly paramagnetic
• It has a half-filled 4f subshell (4f⁷) and is highly paramagnetic
• It is the only lanthanoid that is ferromagnetic

Which of the following best describes the magnetic properties of most Ln³⁺ ions?

• They are typically diamagnetic
• They are typically ferromagnetic
• They are typically paramagnetic
• They exhibit no magnetic properties

What is a primary challenge in the industrial extraction of individual lanthanoids?

• Finding suitable ore deposits
• Extracting them from gaseous compounds
• Separating lanthanoids from each other due to their similar ionic sizes and charges
• Converting them into their metallic form

What is the main source of the intense colors often observed in lanthanoid complexes?

• d-d electronic transitions
• Charge transfer transitions
• f-f electronic transitions within the 4f orbitals
• Metal-to-ligand bonding

Why are the 4f electrons in lanthanoids considered 'inner' electrons?

• They have lower energy than all other electrons
• They are always paired
• They are located in a shell that is closer to the nucleus than the outermost valence electrons
• They are removed first during ionization