d- and f-Block Elements Practice Flashcards

A set of vocabulary flashcards covering the definitions, configurations, and properties of the d- and f-block elements based on the lecture transcript.

d-block elements

Elements of groups 3-12 in the periodic table in which the d orbitals are progressively filled in each of the four long periods.

f-block elements

Elements in which 4f and 5f orbitals are progressively filled, typically placed in a separate panel at the bottom of the periodic table.

Transition metals

According to IUPAC, these are metals which have an incomplete d subshell either in their neutral atom or in their ions.

Inner transition metals

The elements of the f-block, consisting of the lanthanoids and actinoids.

Lanthanoids

The series of fourteen inner transition elements from Cerium ($Ce$, $Z=58$) to Lutetium ($Lu$, $Z=71$).

Actinoids

The series of fourteen inner transition elements from Thorium ($Th$, $Z=90$) to Lawrencium ($Lr$, $Z=103$).

Group 12 elements

Zinc ($Zn$), cadmium ($Cd$), and mercury ($Hg$), which are not regarded as transition metals because they have full $d^{10}$ configurations in ground and common oxidation states.

General electronic configuration (d-block)

Represented by the formula $(n-1)d^{1-10} ns^{1-2}$, with the exception of Palladium ($Pd$) which is $4d^{10} 5s^0$.

Enthalpy of atomisation

The energy required to transition a metal to gaseous atoms; transition metals have high values due to strong interatomic metallic bonding involving $(n-1)d$ and $ns$ electrons.

Lanthanoid contraction

A regular decrease in the atomic and ionic radii ($M^{3+}$) of lanthanoids with increasing atomic number, caused by imperfect shielding of one $4f$ electron by another.

Exchange energy

A factor responsible for stabilizing energy states, approximately proportional to the total number of possible pairs of parallel spins in degenerate orbitals.

Paramagnetism

A magnetic behavior arising from the presence of unpaired electrons, where the substance is attracted by an applied magnetic field.

Spin-only formula

The formula used to calculate magnetic moment ($\mu$) based on the number of unpaired electrons ($n$): $\mu = \sqrt{n(n+2)}$ in units of Bohr magneton (BM).

Bohr magneton (BM)

The unit for magnetic moment; a single unpaired electron has a calculated value of $1.73\,BM$.

Interstitial compounds

Compounds formed when small atoms like $H$, $C$, or $N$ are trapped inside the crystal lattices of transition metals, such as $TiC$ and $Fe_3H$.

Alloy

A blend of metals prepared by mixing the components, forming homogeneous solid solutions if the metallic radii are within about $15\,\%$ of each other.

Disproportionation

The process where a particular oxidation state becomes less stable relative to two other oxidation states, one higher and one lower, such as $3 MnO_4^{2-} + 4 H^+ \rightarrow 2 MnO_4^{-} + MnO_2 + 2H_2O$.

Potassium dichromate ($K_2Cr_2O_7$)

An important orange crystalline chemical prepared from chromite ore ($FeCr_2O_4$), used as an oxidant in the leather industry and volumetric analysis.

Potassium permanganate ($KMnO_4$)

A dark purple crystalline salt prepared from pyrolusite ore ($MnO_2$) that acts as a strong oxidizing agent in acidic, neutral, or alkaline solutions.

Mischmetall

A well-known alloy consisting of a lanthanoid metal (approximately $95\,\%$) and iron (approximately $5\,\%$), used in magnesium-based alloys for bullets and lighter flints.

Actinoid contraction

A gradual decrease in the size of atoms or $M^{3+}$ ions across the actinoid series, which is greater than lanthanoid contraction due to poorer shielding by $5f$ electrons.