Ch 9d and f Block Elements — Class 12 Chemistry, concept-first.

The elements in the long middle stretch of the periodic table -- Groups 3 to 12 -- together with the two 14-element rows conventionally shown below the main table, form what is called the transition a…

The d-block of the periodic table lies between the s-block (Groups 1 and 2) and the p-block (Groups 13-18), occupying Groups 3 to 12.

The general outer electronic configuration of a first-row (3d) transition metal atom is , built on the argon core. Filling this pattern in order of increasing atomic number gives:

Transition metals are, on the whole, considerably less reactive than the s-block metals, and several of them (gold, silver, platinum among the heavier members) occur in the free, uncombined (native) s…

Descending any single group of the periodic table, atomic radius increases steadily because a new principal shell is added at each step.

Ionization enthalpy is the energy required to remove an electron from a gaseous atom or ion. Across a p-block period, this quantity rises in a fairly smooth, predictable way as nuclear charge increase…

Transition metals characteristically show variable oxidation states -- often three, four, or even more distinct states for a single element -- in sharp contrast to the s-block metals, which almost alw…

Compounds of most transition metal ions are strikingly coloured -- solutions blue, solutions green, solutions pink, compounds violet or green, compounds yellow-brown -- while a handful of transition m…

Transition metals and their compounds are among the most important and most widely used catalysts in the chemical industry, in laboratory chemistry, and in biological systems.

A substance is called paramagnetic if it is weakly attracted into an external magnetic field, and diamagnetic if it is weakly repelled by one.

Potassium dichromate, , is manufactured industrially from chromite ore, (an iron-chromium spinel oxide, introduced earlier in this chapter as chromium's principal natural ore), in three successive sta…

Potassium permanganate, , is manufactured industrially from pyrolusite ore, (manganese's principal natural ore, introduced earlier in this chapter), in two successive stages.

The fourteen lanthanoids are the elements cerium (Ce, ) through lutetium (Lu, ), which follow lanthanum (La, ) in the periodic table.

Lanthanoid contraction is the name given to the steady, small, but strictly cumulative decrease in atomic and ionic radius observed across the fourteen lanthanoid elements, from lanthanum to lutetium.

Lanthanoids and their compounds find a range of important practical applications, many of which exploit either their characteristic magnetic and optical (f-f transition) properties or the ease with wh…

The fourteen actinoids are the elements thorium (Th, ) through lawrencium (Lr, ), which follow actinium (Ac, ) in the periodic table.

This chapter developed the chemistry of the d-block transition metals and the f-block inner-transition elements as prescribed by the WBCHSE Semester IV syllabus.

Sample papers and previous-year board questions for this subject.