The d- and f-Block Elements

The d- and f-Block ElementsNEET Chemistry · Class 12 · NCERT Chapter 4

Overview Notes NEET Questions Interactive Learning

2 interactive concept widgets for The d- and f-Block Elements. Drag any slider, change any number, and watch the formula and the answer update live. Built so you understand how each NEET problem actually works, not just the final number.

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Transition metals: electronic config, oxidation states, magnetic moment, and colour for Sc-Zn

Transition metal compounds: oxidation state calculation, d-electron count, magnetic character

First-row transition metals explorer

Click any element from Sc to Zn to see its electronic configuration, common oxidation states, magnetic moment, and aqueous ion colour. Exceptions (Cr, Cu) are highlighted.

d-Block elements

First-row transition metals: configuration, oxidation states, and colour

Click any element to see its electronic configuration, common oxidation states, magnetic moment, and aqueous ion colour. Exceptions (Cr and Cu) are highlighted.

Manganese (Mn) — Z = 25

Atomic config

[Ar] 3d⁵ 4s²

Mn²⁺ config

[Ar] 3d⁵

Oxidation states

+2, +3, +4, +6, +7

Unpaired e⁻ (common ion)

Magnetic moment μ

5.92 BM

Aqueous ion colour

Pale pink (Mn²⁺)

Widest range of oxidation states. MnO₄⁻ (Mn⁷⁺) is purple; MnO₂ is black.

Try this

Cr ([Ar] 3d⁵ 4s¹) and Cu ([Ar] 3d¹⁰ 4s¹) are the two exceptions. Click them to see why.
Mn has the highest number of unpaired electrons (5) and magnetic moment (5.92 BM). Fe³⁺ also has 5 unpaired electrons.
Zn²⁺ is colourless and diamagnetic (d¹⁰) — a common NEET trap. Sc³⁺ is also colourless (d⁰).

Oxidation states and d-electron count

Select a transition metal compound to see the metal's oxidation state, d-electron configuration, unpaired electrons, and magnetic moment. Step-by-step working shown.

Oxidation states

Transition metal oxidation states and d-electron count

Select a compound to see the metal's oxidation state, d-electron configuration, unpaired electrons, and magnetic moment. Step-by-step oxidation state calculation is shown.

Select compound

Metal

Oxidation state

d-electrons

3d0

Unpaired electrons

Magnetic moment

0 (diamagnetic)

How to find oxidation state

K is +1, each O is -2. +1 + Mn + 4(-2) = 0. Mn = +7.

Mn⁷⁺ has d⁰ configuration. Purple colour comes from charge-transfer, not d-d transitions.

Try this

KMnO₄ and K₂Cr₂O₇ have d⁰ metals — their colour comes from charge-transfer, not d-d transitions. Select them to confirm.
Compare FeCl₃ (Fe³⁺, 3d⁵) and FeSO₄ (Fe²⁺, 3d⁶) — different oxidation states, different magnetic moments.
CuCl has Cu⁺ (3d¹⁰): colourless and diamagnetic. CuSO₄ has Cu²⁺ (3d⁹): blue and paramagnetic.

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