d-Block Elements
Transition elements whose last electron enters a d orbital, in groups 3 to 12.
Practise Atomic Structure & Periodicity All Atomic Structure & Periodicity topics
Transition elements whose last electron enters a d orbital, in groups 3 to 12.
Practise Atomic Structure & Periodicity All Atomic Structure & Periodicity topics
The d-block consists of transition metals in groups 3 to 12, whose last electron enters a d orbital. Their partly filled d subshells give them variable oxidation states, coloured ions, catalytic activity and a strong tendency to form complexes. They are generally hard, dense metals with high melting points. Many transition metals and their compounds are used as industrial catalysts. Zinc, cadmium and mercury are sometimes excluded from the strict definition, since their d subshells are full.
Key ideas: Groups 3 to 12, filling (n-1)d subshell, ns2 or ns1 valence. They show variable oxidation states, colored compounds (d-d transitions), paramagnetism, complex ion formation and catalytic activity. Typical states: Fe +2 and +3, Mn +2 to +7, Cr +3 and +6. They are hard, high melting, good conductors, with similar atomic radius across the series.
Common mistakes and connections: Students think Zn, Cd and Hg are transition metals; with full d10 they are d-block but not strictly transition elements. Also they say d electrons are removed first; the ns electrons leave first. Variable valency arises from similar ns and (n-1)d energies. These topics feed into coordination chemistry.
Melting points of the 3d metals are high because d electrons add to metallic bonding, then drop sharply for zinc with its full d subshell. The interactive lesson shows this as a live animation or chart.
Iron commonly exists as Fe2+ or Fe3+, and these ions give pale green and yellow-brown compounds respectively.
Transition elements whose last electron enters a d orbital, in groups 3 to 12.
d-Block Elements is a beginner topic in Atomic Structure & Periodicity. It needs no earlier chemistry lessons and is a good starting point.
Study these earlier topics in Atomic Structure & Periodicity first: Periods and Groups, s-Block Elements, p-Block Elements.
The next topics in Atomic Structure & Periodicity are f-Block Elements and Metals Nonmetals and Metalloids.
Yes. The interactive lesson includes a self-check question on d-Block Elements, and the Atomic Structure & Periodicity quiz draws on every topic in this area.
d-Block Elements is topic 80 of 115 in Atomic Structure & Periodicity.