The d- and f- Block Elements

Vocabulary flashcards focusing on the electronic configurations, physical properties, chemical reactions, and specific compounds of the d-block and f-block elements based on the lecture transcript.

The enthalpy change required to separate metal atoms, which is high in transition metals due to strong interatomic metallic bonding between $(n-1)d$ and $ns$ electrons.

Enthalpy of atomisation

A stabilizing factor for energy states proportional to the total number of possible pairs of parallel spins in degenerate orbitals, such as in $d^5$ configurations.

Exchange energy

The process where a particular oxidation state becomes less stable relative to a lower and a higher oxidation state, such as $3 Mn^{VI}O_4^{2-} + 4 H^+ \rightarrow 2 Mn^{VII}O_4^- + Mn^{IV}O_2 + 2 H_2O$.

Disproportionation

A magnetic property arising from the presence of unpaired electrons, causing substances to be attracted by an applied magnetic field.

Paramagnetism

Non-stoichiometric compounds formed when small atoms like $H$, $C$, or $N$ are trapped inside the crystal lattices of transition metals.

Interstitial compounds

Homogeneous solid solutions prepared by mixing metal components, typically formed by transition metals with atomic radii within $15\%$ of each other.

Alloys

An alloy consisting of approximately $95\%$ lanthanoid metal and $5\%$ iron, with traces of $S$, $C$, $Ca$, and $Al$, used in magnesium-based alloys for bullets and lighter flints.

Mischmetall

An orange crystalline compound used as a strong oxidizing agent in organic chemistry and as a primary standard in volumetric analysis.

Potassium dichromate ($K_2Cr_2O_7$)

A dark purple, diamagnetic compound prepared from pyrolusite ore ($MnO_2$) that acts as a strong oxidant in analytical chemistry.

Potassium permanganate ($KMnO_4$)

A gradual decrease in the size of atoms or $M^{3+}$ ions across the actinoid series resulting from poor shielding by 5f electrons.

Actinoid contraction

A catalyst composed of titanium tetrachloride ($TiCl_4$) and triethylaluminium ($Al(CH_3)_3$) used for manufacturing polyethylene.

Ziegler catalyst

Palladium(II) chloride ($PdCl_2$), which catalyzes the oxidation of ethyne to ethanal.

Wacker process catalyst