---
title: "d-block elements; 3d configuration; non-typical metals"
subject: "Engineering Chemistry"
chapter: 5
key: "semester_2/engineering_chemistry:dblock-config-not-typical"
source: https://www.bctengineer.com/q/semester_2/engineering_chemistry/dblock-config-not-typical
site: BCT Engineering
---

# d-block elements; 3d configuration; non-typical metals

Engineering Chemistry · Chapter 5: 3-d Transition Elements and their Applications

- Asked in: 2067 Chaitra, 1+2+2 marks
- Video: [d block, transition & non transition elements,general electron configuration, Lanthanoids, actinoids](https://www.youtube.com/watch?v=5Vay32_wMc4) — Tushar Sir's Chemistry
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_2/engineering_chemistry/dblock-config-not-typical
- Whole chapter: https://www.bctengineer.com/md/semester_2/engineering_chemistry/chapter-5

## Question

What are d-block elements? Give the electronic configuration of 3d series. Mention which d block metals are not considered as transition metals and why?

## Short answer

d-block elements have the last electron entering (n-1)d. 3d series configurations: Sc [Ar]3d¹4s² to Zn [Ar]3d¹⁰4s²; Cr [Ar]3d⁵4s¹ and Cu [Ar]3d¹⁰4s¹ are exceptions. Zn, Cd, Hg are not transition metals because their atoms and M²⁺ ions have d¹⁰, so no incomplete d-orbital; they lack variable valency and typical transition properties.

## Answer

#### d-block elements
Elements in which the last electron enters the (n−1)d subshell. They are in groups 3 to 12 of the periodic table.

#### Configuration of the 3d series
```text
Sc  [Ar] 3d¹ 4s²     Fe  [Ar] 3d⁶ 4s²
Ti  [Ar] 3d² 4s²     Co  [Ar] 3d⁷ 4s²
V   [Ar] 3d³ 4s²     Ni  [Ar] 3d⁸ 4s²
Cr  [Ar] 3d⁵ 4s¹     Cu  [Ar] 3d¹⁰ 4s¹
Mn  [Ar] 3d⁵ 4s²     Zn  [Ar] 3d¹⁰ 4s²
```
Cr and Cu are exceptions: a half-filled (d⁵) or completely filled (d¹⁰) 3d subshell is extra stable, so one 4s electron moves into 3d.

#### Metals not considered transition metals
**Zn, Cd and Hg** (group 12). Their atoms and common ions (M²⁺) have a completely filled d¹⁰ subshell, so they have no incomplete d orbital in any common state. They do not show typical transition properties: no variable valency, colourless diamagnetic compounds, and low melting points (Hg is liquid). Sc is sometimes also named, as Sc³⁺ has a d⁰ configuration.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What are d-block elements?
   A. Elements whose last electron enters ns
   B. Elements whose last electron enters the (n-1)d subshell
   C. Elements whose last electron enters np
   D. Elements with no electrons in d
   Answer: B. They are in groups 3 to 12. (Key point: d-block)

2. What is Ni?
   A. [Ar] 3d10 4s0
   B. [Ar] 3d6 4s2
   C. [Ar] 3d8 4s2
   D. [Ar] 3d9 4s1
   Answer: C. Ni: [Ar] 3d8 4s2. (Key point: Configuration)

3. Which d-block metals are not considered transition metals?
   A. Fe, Co and Ni
   B. Cr, Mn and V
   C. Cu, Ag and Au
   D. Zn, Cd and Hg
   Answer: D. Group 12 has d10 in atom and M2+. (Key point: Non-transition metals)

## Related in Engineering Chemistry

- [Transition elements; non-typical 3d element](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Atm-not-typical) — Engineering Chemistry, chapter 5
- [Zn and Cd not typical transition metals](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Azn-cd-not-typical) — Engineering Chemistry, chapter 5
- [Transition elements; first series configuration](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Awhy-transition-elements-typical) — Engineering Chemistry, chapter 5
- [General outer electronic configuration of transition elements](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Atm-general-config) — Engineering Chemistry, chapter 5
- [Transition elements; why so called; 3d configurations](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Atm-called-config) — Engineering Chemistry, chapter 5
- [Characteristics of transition series; first-row configuration](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Atm-characteristics-config) — Engineering Chemistry, chapter 5

## Related in other subjects

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