D

D-Transition Elements (Metals)

d-block: [noble gas](n-1)d^(1-10)ns^(0-2)
Quick Reference
Formula / Notationd-block: [noble gas](n-1)d^(1-10)ns^(0-2)
Also Known AsTransition metals; d-block elements; transition elements; inner d-series metals; TM elements

What is D-Transition Elements (Metals)?

D-transition elements (also called transition metals or d-block elements) are elements in which the d orbitals are progressively filled. They occupy Groups 3–12 of the periodic table. They are characterised by variable oxidation states, formation of coloured compounds, catalytic activity, and ability to form complex ions. Examples include iron, copper, zinc, chromium, and titanium.

Formula & Notation

d-block: [noble gas](n-1)d^(1-10)ns^(0-2)

Other Names / Synonyms: Transition metals; d-block elements; transition elements; inner d-series metals; TM elements

Properties & Characteristics

Filling of (n-1)d subshell; Groups 3–12; 4 periods (3d, 4d, 5d, 6d); variable oxidation states; form coloured compounds; paramagnetic (unpaired d electrons); good conductors; high melting points; form complex ions with ligands; catalytically active; high density

Uses & Applications

Structural metals (iron, steel); catalysts (Fe in Haber process, Pt in catalytic converters, Ni in hydrogenation); electronics (Cu wiring, Ti in microelectronics); pigments (Cr₂O₃ green, CuSO₄ blue); stainless steel; biomedical implants (Ti, Co-Cr alloys)

Safety Information

Varies by element. Heavy transition metals (Cd, Hg, Pb — though Pb is not strictly d-block) are highly toxic. Chromium(VI) compounds are carcinogenic. Nickel compounds are allergenic and suspected carcinogens. Fine metal dusts are respiratory hazards. Always follow SDS guidelines.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term D-Transition Elements (Metals)
Formula d-block: [noble gas](n-1)d^(1-10)ns^(0-2)
Synonyms Transition metals; d-block elements; transition elements; inner d-series metals; TM elements

Frequently Asked Questions

D-transition elements (also called transition metals or d-block elements) are elements in which the d orbitals are progressively filled. They occupy Groups 3–12 of the periodic table. They are characterised by variable oxidation states, formation of coloured compounds, catalytic activity, and ability to form complex ions. Examples include iron, copper, zinc, chromium, and titanium.

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