Join WhatsApp Icon JEE WhatsApp Group
Question 45

In which of the following pairs, the outermost electronic configuration will be the same?

We need to find which pair of ions has the same outermost electronic configuration by writing the configurations for each ion.

For Option 1: Chromium (Z = 24) has the neutral configuration $$[Ar]\,3d^5\,4s^1$$ (anomalous due to half-filled d-orbital stability). Removing one electron from the 4s orbital gives $$Cr^+ = [Ar]\,3d^5$$. Manganese (Z = 25) has the neutral configuration $$[Ar]\,3d^5\,4s^2$$. Removing two electrons (both from 4s) gives $$Mn^{2+} = [Ar]\,3d^5$$. Both ions have identical $$3d^5$$ configurations.

For Option 2: Nickel (Z = 28) gives $$Ni^{2+} = [Ar]\,3d^8$$ (removing two 4s electrons from $$[Ar]\,3d^8\,4s^2$$). Copper (Z = 29) has the neutral configuration $$[Ar]\,3d^{10}\,4s^1$$. Removing the 4s electron gives $$Cu^+ = [Ar]\,3d^{10}$$. Since $$3d^8 \neq 3d^{10}$$, these do not match.

For Option 3: Iron (Z = 26) gives $$Fe^{2+} = [Ar]\,3d^6$$. Cobalt (Z = 27) has the neutral configuration $$[Ar]\,3d^7\,4s^2$$. Removing one electron from 4s gives $$Co^+ = [Ar]\,3d^7\,4s^1$$. Since $$3d^6 \neq 3d^7\,4s^1$$, these do not match.

For Option 4: Vanadium (Z = 23) gives $$V^{2+} = [Ar]\,3d^3$$. We already found $$Cr^+ = [Ar]\,3d^5$$. Since $$3d^3 \neq 3d^5$$, these do not match.

Therefore, the correct answer is Option 1: $$Cr^+$$ and $$Mn^{2+}$$, both having the outermost electronic configuration $$3d^5$$.

Get AI Help

Create a FREE account and get:

  • Free JEE Mains Previous Papers PDF
  • Take JEE Mains paper tests

JEE Quant Questions | JEE Quantitative Ability

JEE DILR Questions | LRDI Questions For JEE

JEE Verbal Ability Questions | VARC Questions For JEE

Free JEE Topicwise Questions

JEE Rotational MotionJEE Units & MeasurementsJEE Atomic StructureJEE GravitationJEE Periodic Table & PeriodicityJEE StatisticsJEE Inverse Trigonometric FunctionsJEE Magnetism & Magnetic MaterialsJEE Sequences & SeriesJEE MatricesJEE Alternating CurrentsJEE Carboxylic AcidsJEE Permutations & CombinationsJEE Work, Energy & PowerJEE Electromagnetic InductionJEE Electronic DevicesJEE d and f-Block ElementsJEE Chemical KineticsJEE Heat TransferJEE Three Dimensional GeometryJEE Magnetic Effects of CurrentJEE Hydrocarbons - AromaticJEE Electromagnetic WavesJEE Aldehydes & KetonesJEE Hydrocarbons - AlkanesJEE Applications of DerivativesJEE EquilibriumJEE Indefinite IntegrationJEE Chemical ThermodynamicsJEE ElectrochemistryJEE ProbabilityJEE BiomoleculesJEE Continuity & DifferentiabilityJEE Kinetic Theory of GasesJEE Vector AlgebraJEE Hydrocarbons - AlkynesJEE Differential EquationsJEE Current & ResistanceJEE Straight LinesJEE WavesJEE Redox ReactionsJEE Hydrocarbons - AlkenesJEE DeterminantsJEE SolutionsJEE Ray OpticsJEE Dual Nature of Matter & RadiationJEE Chemical Bonding & Molecular StructureJEE Complex NumbersJEE Sets, Relations & FunctionsJEE Electric Charges & FieldsJEE Laws of MotionJEE Fluid MechanicsJEE Basic Concepts in ChemistryJEE Trigonometric FunctionsJEE LimitsJEE Laws of ThermodynamicsJEE Kinematics - 2D MotionJEE p-Block Elements (Groups 13-18)JEE Simple Harmonic MotionJEE Electric Potential & CapacitanceJEE Coordination CompoundsJEE JEE 2D GeometryJEE CirclesJEE Definite IntegrationJEE EMF & Circuit AnalysisJEE Surface TensionJEE Atoms & NucleiJEE Laboratory Experiments - XIJEE Number SystemJEE Basic Principles of Organic ChemistryJEE Wave OpticsJEE Quadratic EquationsJEE Alcohols, Phenols & EthersJEE Organic Compounds with HalogensJEE DifferentiationJEE Conic SectionsJEE Nitrogen-Containing CompoundsJEE ElasticityJEE Practical Organic ChemistryJEE Kinematics - 1D MotionJEE Purification & CharacterisationJEE Binomial Theorem
Ask AI