JEE Main202228 Jul 2022Evening ShiftChemistryStructure of AtomActual
Which of the following pair is not isoelectronic species? (Atomic numbers Sm = 62 ; Er = 68 ; Yb = 70 ; Lu = 71 ; Eu = 63 ; Tb = 65 ; Tm = 69 )
Options
- ASm 2 + and Er 3 +
- BYb 2 + and Lu 3 +
- CEu 2 + and Tb 4 +
- DTb 2 + and Tm 4 +
Correct answer
D. Tb 2 + and Tm 4 +
Step-by-step solution
Isoelectronic species refers to two atoms, ions or molecules that have the same electronic structure and the same number of valence electrons term means "equal electric" or "equal charge". Isoelectronic chemical species typically display similar chemical properties. Sm 2 + → electron = 60 Er 3 + → electron = 65   Tb 2 + → electron = 63 Tm 4 + → electron = 65 (not isoelectronic) While Yb 2 + and Lu 3 + both will have 68 electrons. and Eu 2 + and Tb 4 + both will have 61 electrons.so, the