JEE Mains · Chemistry · STD 11 - 2. structure of atom
Which of the following pair is not isoelectronic species? (At. no. \(Sm , 62 ; Er , 68: Yb , 70: Lu , 71 ; Eu , 63: Tb\), \(65\); \(\operatorname{Tm}, 69)\)
- A \(Sm ^{2+}\) and \(Er ^{3+}\)
- B \(Yb ^{2+}\) and \(Lu ^{3+}\)
- C \(Tb ^{2+}\) and \(Tm ^{4+}\)
- D both \((A)\) and \((C)\) are true
Answer & Solution
Correct Answer
(D) both \((A)\) and \((C)\) are true
Step-by-step Solution
Detailed explanation
\(Sm ^{2+} \rightarrow\) electron \(=60\) \(Er ^{3+} \rightarrow\) electron \(=65\) \(Tb ^{2+} \rightarrow\) electron \(=63\) \(Tm ^{4+} \rightarrow\) electron \(=65\) all are \((not\,isoelectronic)\)
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