NEET Solved Paper 2014 Question 19

Question: $ B{e^{2+}} $ is isoelectronic with which of the following ions? [AIPMT 2014]

Options:

A) $ {H^{+}} $

B) $ L{i^{+}} $

C) $ N{a^{+}} $

D) $ M{g^{2+}} $

Show Answer

Answer:

Correct Answer: B

Solution:

  • Isoelectronic species contain same number of electrons. $ B{e^{2+}} $ contains 2 electrons. Among the given options, only $ L{i^{2+}} $ contains 2 electrons and therefore, it is isoelectronic with $ B{e^{2+}} $ . $ {H^{+}}\to $ no electron; $ N{a^{+}}\to 10{e^{-}} $ $ L{i^{+}}\to 2{e^{-}};M{g^{2+}}\to 10{e^{-}} $ Hence, $ B{e^{2+}} $ is isoelectronic with $ L{i^{+}} $ .