Question

Which of the following pair is not isoelectronic species?
(At. no. $Sm,62;Er,68:Yb,70:Lu,71;Eu,63:Tb,65;Tm,69$)

• A. $S{m}^{2+}$ and $E{r}^{3+}$
• B. $Y{b}^{2+}$ and $L{u}^{3+}$
• C. $E{u}^{2+}$ and $T{b}^{4+}$
• D. $T{b}^{2+}$ and $T{m}^{4+}$

Answer 1

Answer: (A), (D)

Correct answer is (a) $S{m}^{2+}$ and $E{r}^{3+}$ Correct answer is (d) $T{b}^{2+}$ and $T{m}^{4+}$