d and f BLOCK ELEMENTS

What can be inferred about the magnetic moment of [Fe(H2O)6]^2+ having a value of 5.3 BM?

• It indicates six unpaired electrons, a high-spin configuration.
• It indicates four unpaired electrons, suggesting a high-spin d^6 configuration for Fe(II).
• It indicates two unpaired electrons, a low-spin configuration.
• It indicates the complex is paramagnetic with one unpaired electron.

What can be inferred about the magnetic moment of K4[Mn(CN)6] having a value of 2.2 BM?

• It indicates five unpaired electrons, a high-spin configuration.
• It indicates the presence of one unpaired electron, suggesting a low-spin d^5 configuration for Mn(II).
• It indicates three unpaired electrons.
• It indicates the complex is diamagnetic.

Why do the first transition series elements often show different properties compared to the heavier transition elements?

• Because they are lighter.
• Due to differences in atomic size, nuclear charge, and the influence of Lanthanoid/Actinoid contractions on subsequent periods.
• Because they were discovered first.
• Because they are less reactive.

In what significant ways do the properties of the first transition series (3d elements) differ from those of the heavier transition series (4d and 5d elements)?

• First series elements have larger atomic sizes.
• First series elements generally have smaller atomic sizes, lower densities, lower enthalpies of atomization, and exhibit lower maximum oxidation states compared to heavier series.
• Heavier series elements have lower melting points.
• There are no significant differences.

How many 3d electrons are present in the Cu^2+ ion, and how would they be expected to occupy the d-orbitals in an octahedral complex (assuming a weak field ligand like water)?

• 11 electrons; t2g^11 eg^0
• 9 electrons; t2g^6 eg^3
• 1 electron; t2g^1 eg^0
• 9 electrons; t2g^9 eg^0