AP EAMCET20225 Jul 2022Morning ShiftChemistryStructure of AtomActual
Identify the isoelectronic pair of ions from the following.
Options
- APr ³⁺, Nd ³⁺
- BTb ³⁺, Dy ²⁺
- CEu ²⁺, Gd ³⁺
- DPr ³⁺, Ce ⁴⁺
Correct answer
C. Eu ²⁺, Gd ³⁺
Step-by-step solution
Isoelectronic species have same number of electrons in them. (a) Pr ³⁺ number of electron =59-3=56 Nd ³⁺ number of electron =60-3=57 Pr ³⁺ and Nd ³⁺ are not isoelectronic. (b) Tb ³⁺ : Total number of electron =65-3=62 Dy ²⁺ : Total number of electron =66-2=64 Tb ³⁺ and Dy ²⁺ are not isoelectronic. (c) Eu ²⁺ number of electron =63-2=61 Gd ³⁺ number of electron =64-3=61 Eu ²⁺ and Gd ³⁺ are isoelectronic. (d) Pr ³⁺ number of electron =59-3=56 Ce ⁴⁺ number of electron =58-4=54 Pr ³⁺ and Ce ⁴⁺ are not isoelectronic.