Which one of the lanthanoids given below is the most stable in divalent form?
- Ce (Atomic Number 58)
- Sm (Atomic Number 62 )
- Eu (Atomic Number 63)
- Yb (Atomic Number 70)
The Correct Option is C
Solution and Explanation
The correct answer is (C) : Eu (Atomic Number 63)
Yb+2 is 4f14
Eu+2 is 4f7
but Eu+2 is more stable than Yb+2 because
\(E°_{Eu|Eu^{2+}} > E°_{Yb|Yb^{2+}}\)
Top Questions on The Lanthanoids
- Which trend is correct regarding ionic radius in the 4f-series (lanthanides)?
- MHT CET - 2025
- Chemistry
- The Lanthanoids
- The first and second ionization enthalpies of lanthanoids are comparable with the element
- KEAM - 2025
- Chemistry
- The Lanthanoids
- What is the formula of lanthanoids with sulfur?
- KEAM - 2025
- Chemistry
- The Lanthanoids
- Number of colourless lanthanoid ions among the following is ____.
\[ \text{Eu}^{3+}, \, \text{Lu}^{3+}, \, \text{Nd}^{3+}, \, \text{La}^{3+}, \, \text{Sm}^{3+} \]- JEE Main - 2024
- Chemistry
- The Lanthanoids
- The Lanthanoid ion which would form coloured compounds is ------------.
Atomic numbers: Yb = 70, Lu = 71, Pr = 59, La = 57- COMEDK UGET - 2024
- Chemistry
- The Lanthanoids
Questions Asked in JEE Main exam
Nature of compounds TeO₂ and TeH₂ is___________ and ______________respectively.
- JEE Main - 2025
- Inorganic chemistry
- Let \( A = [a_{ij}] \) be a matrix of order 3 \(\times\) 3, with \(a_{ij} = (\sqrt{2})^{i+j}\). If the sum of all the elements in the third row of \( A^2 \) is \( \alpha + \beta\sqrt{2} \), where \(\alpha, \beta \in \mathbb{Z}\), then \(\alpha + \beta\) is equal to:
- JEE Main - 2025
- Matrices and Determinants
Consider the following sequence of reactions :
Molar mass of the product formed (A) is ______ g mol\(^{-1}\).- JEE Main - 2025
- Organic Chemistry
The magnitude of heat exchanged by a system for the given cyclic process ABC (as shown in the figure) is (in SI units):
- JEE Main - 2025
- Electric charges and fields
- The value of \( (\sin 70^\circ)(\cot 10^\circ \cot 70^\circ - 1) \) is:
- JEE Main - 2025
- Trigonometric Identities
Concepts Used:
Lanthanoids
Lanthanoids are at the top of these two-row, while actinoids are at the bottom row.
Properties of Lanthanoids
Lanthanoids are inclusive of 14 elements, with atomic numbers 58-71:
- Cerium - Xe 4f1 5d1 6s2
- Praseodymium - Xe 4f3 6s2
- Neodymium - Xe 4f4 6s2
- Promethium - Xe 4f5 6s2
- Samarium - Xe 4f6 6s2
- Europium - Xe 4f7 6s2
- Gadolinium - Xe 4f7 5d1 6s2
- Terbium - Xe 4f9 6s2
- Dysprosium - Xe 4f10 6s2
- Holmium - Xe 4f11 6s2
- Erbium - Xe 4f12 6s2
- Thulium - Xe 4f13 6s2
- Ytterbium - Xe 4f14 6s2
- Lutetium - Xe 4f14 5d1 6s2
These elements are also called rare earth elements. They are found naturally on the earth, and they're all radioactively stable except promethium, which is radioactive. A trend is one of the interesting properties of the lanthanoid elements, called lanthanide contraction.