JEE Challenger
More from d and f Block Elements
ChemMedMain 2026 • 2nd Apr - Shift 2

Number of Paramagnetic Metal Ions Among d and f Block Elements

Number of paramagnetic ions among the following d- and f-block metal ions is ______ . Mn2+,Cu2+,Zn2+,Yb2+,Sc3+,La3+,Gd3+,Lu3+,Ti4+,Ce4+\text{Mn}^{2+}, \text{Cu}^{2+}, \text{Zn}^{2+}, \text{Yb}^{2+}, \text{Sc}^{3+}, \text{La}^{3+}, \text{Gd}^{3+}, \text{Lu}^{3+}, \text{Ti}^{4+}, \text{Ce}^{4+} (Atomic number of Mn=25,Cu=29,Zn=30,Yb=70,Sc=21,La=57,Gd=64,Lu=71,Ti=22,Ce=58\text{Mn}=25, \text{Cu}=29, \text{Zn}=30, \text{Yb}=70, \text{Sc}=21, \text{La}=57, \text{Gd}=64, \text{Lu}=71, \text{Ti}=22, \text{Ce}=58)

Official Numerical Answer3

Topics & Concepts

d and f Block Elementsd-Block Elementsf-Block ElementsElectronic Configuration

Step-by-Step Solution

To determine the number of paramagnetic metal ions among the given list, we examine the electronic configuration of each ion and check for the presence of unpaired electrons:

  1. Mn2+\text{Mn}^{2+} (Z=25Z = 25):

    • Electronic configuration of Mn\text{Mn}: [Ar] 3d54s2[\text{Ar}]\, 3d^5 4s^2
    • Electronic configuration of Mn2+\text{Mn}^{2+}: [Ar] 3d5[\text{Ar}]\, 3d^5
    • Unpaired electrons: n=5n = 5   ⟹  \implies Paramagnetic

  2. Cu2+\text{Cu}^{2+} (Z=29Z = 29):

    • Electronic configuration of Cu\text{Cu}: [Ar] 3d104s1[\text{Ar}]\, 3d^{10} 4s^1
    • Electronic configuration of Cu2+\text{Cu}^{2+}: [Ar] 3d9[\text{Ar}]\, 3d^9
    • Unpaired electrons: n=1n = 1   ⟹  \implies Paramagnetic

  3. Zn2+\text{Zn}^{2+} (Z=30Z = 30):

    • Electronic configuration of Zn\text{Zn}: [Ar] 3d104s2[\text{Ar}]\, 3d^{10} 4s^2
    • Electronic configuration of Zn2+\text{Zn}^{2+}: [Ar] 3d10[\text{Ar}]\, 3d^{10}
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

  4. Yb2+\text{Yb}^{2+} (Z=70Z = 70):

    • Electronic configuration of Yb\text{Yb}: [Xe] 4f146s2[\text{Xe}]\, 4f^{14} 6s^2
    • Electronic configuration of Yb2+\text{Yb}^{2+}: [Xe] 4f14[\text{Xe}]\, 4f^{14}
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

  5. Sc3+\text{Sc}^{3+} (Z=21Z = 21):

    • Electronic configuration of Sc\text{Sc}: [Ar] 3d14s2[\text{Ar}]\, 3d^1 4s^2
    • Electronic configuration of Sc3+\text{Sc}^{3+}: [Ar][\text{Ar}]
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

  6. La3+\text{La}^{3+} (Z=57Z = 57):

    • Electronic configuration of La\text{La}: [Xe] 5d16s2[\text{Xe}]\, 5d^1 6s^2
    • Electronic configuration of La3+\text{La}^{3+}: [Xe][\text{Xe}]
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

  7. Gd3+\text{Gd}^{3+} (Z=64Z = 64):

    • Electronic configuration of Gd\text{Gd}: [Xe] 4f75d16s2[\text{Xe}]\, 4f^7 5d^1 6s^2
    • Electronic configuration of Gd3+\text{Gd}^{3+}: [Xe] 4f7[\text{Xe}]\, 4f^7
    • Unpaired electrons: n=7n = 7   ⟹  \implies Paramagnetic

  8. Lu3+\text{Lu}^{3+} (Z=71Z = 71):

    • Electronic configuration of Lu\text{Lu}: [Xe] 4f145d16s2[\text{Xe}]\, 4f^{14} 5d^1 6s^2
    • Electronic configuration of Lu3+\text{Lu}^{3+}: [Xe] 4f14[\text{Xe}]\, 4f^{14}
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

  9. Ti4+\text{Ti}^{4+} (Z=22Z = 22):

    • Electronic configuration of Ti\text{Ti}: [Ar] 3d24s2[\text{Ar}]\, 3d^2 4s^2
    • Electronic configuration of Ti4+\text{Ti}^{4+}: [Ar][\text{Ar}]
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

  10. Ce4+\text{Ce}^{4+} (Z=58Z = 58):

    • Electronic configuration of Ce\text{Ce}: [Xe] 4f15d16s2[\text{Xe}]\, 4f^1 5d^1 6s^2
    • Electronic configuration of Ce4+\text{Ce}^{4+}: [Xe][\text{Xe}]
    • Unpaired electrons: n=0n = 0   ⟹  \implies Diamagnetic

Thus, the paramagnetic ions are Mn2+\text{Mn}^{2+}, Cu2+\text{Cu}^{2+}, and Gd3+\text{Gd}^{3+}.

Therefore, the total number of paramagnetic metal ions is 3.

Number of Paramagnetic Metal Ions Among d and f Block Elements | Chemistry PYQ Solution - JEE Challenger