The number of elements from the following that do not belong to lanthanoids is: Eu, Cm, Er, Tb, Yb and Lu
d & f-Block Elements · Class 12 · JEE Main Previous Year Question
The number of elements from the following that do not belong to lanthanoids is:
and
- a
3
- b
4
- c✓
1
- d
5
1
Lanthanoids: Elements with Z = 57 (La) to 71 (Lu) — filling 4f orbitals.
Checking each element:
| Element | Z | Lanthanoid? | |---------|---|-------------| | Eu (Europium) | 63 | Yes ✓ | | Cm (Curium) | 96 | No ✗ (Actinoid) | | Er (Erbium) | 68 | Yes ✓ | | Tb (Terbium) | 65 | Yes ✓ | | Yb (Ytterbium) | 70 | Yes ✓ | | Lu (Lutetium) | 71 | Yes ✓ |
Only Cm (Z=96) is NOT a lanthanoid — it is an actinoid (5f series).
Count = 1
Answer: Option (3) — 1
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More JEE Main d & f-Block Elements PYQs
Which of the following acts as a strong reducing agent? (Atomic number: Ce = 58, Eu = 63, Gd = 64, Lu = 71)
Diamagnetic Lanthanoid ions are:
Nd2+ = ____
The 'f' orbitals are half and completely filled, respectively in lanthanide ions. [Given: Atomic No. Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb, 70; Dy, 66]
The correct order of atomic radii is: