d and f BLOCK ELEMENTS

Why are interstitial compounds particularly well known for transition metals?

• Transition metals are more reactive.
• They have larger atomic radii.
• The crystal lattices of transition metals have suitable interstitial sites for small atoms.
• They have lower melting points.

What are interstitial compounds?

• Compounds formed by replacing metal atoms.
• Ionic compounds with large anions.
• Compounds formed when small atoms like H, C, N occupy the interstices (holes) in the crystal lattice of transition metals.
• Alloys formed by mixing different metals.

Why do transition metals and their compounds act as good catalysts?

• They are highly reactive in their elemental form.
• They have low melting points.
• They can adopt multiple oxidation states and form complexes.
• They are always in a gaseous state.

Why do transition metals generally form colored compounds?

• They absorb all wavelengths of light.
• They reflect all wavelengths of light.
• d-d transitions of electrons absorbing specific wavelengths of visible light.
• They lack d-electrons.

Why are the enthalpies of atomization of transition metals generally high?

• Weak interatomic forces.
• Low melting points.
• Strong metallic bonding involving both s and d electrons.
• Presence of only s-electrons.