d and f BLOCK ELEMENTS

How does Lanthanoid Contraction affect the basicity of Lanthanoid hydroxides?

• It increases the basic character.
• It has no effect on basicity.
• It generally decreases the basic character.
• It makes them amphoteric.

What is the primary reason Lanthanoid Contraction occurs?

• Increased electron-electron repulsion
• Increased nuclear charge alone
• Poor shielding of outer electrons by 4f electrons leads to increased effective nuclear charge.
• Formation of anions

Why do transition metals have variable oxidation states, unlike alkali metals?

• They have more electrons.
• They are more electronegative.
• The energy difference between (n-1)d and ns orbitals is relatively small.
• They have larger atomic radii.

What is the effect of increasing the crystal field splitting energy (Δ) on the color of a transition metal complex?

• It makes the complex colorless.
• It shifts the absorbed light towards lower energy (longer wavelength).
• It shifts the absorbed light towards higher energy (shorter wavelength), changing the observed color.
• It has no effect on color.

Why is the +2 oxidation state so prevalent among transition metals in the first transition series?

• It always results in a noble gas configuration.
• It involves the loss of d-electrons.
• It corresponds to the loss of the two outermost ns electrons, which are relatively easier to remove.
• It is the highest oxidation state possible.