NEETChemistryClassification of Elements and Periodicity in Properties
Match List I with List II. List I List II (A) Element with the most negative electron gain enthalpy (I) Na (B) Element with the lowest first ionization enthalpy in Period 3 (II) K ⁺ (C) Cation which is isoelectronic with Argon (III) Cs (D) Alkali metal with the largest atomic radius (IV) Cl Choose the correct answer from the options given below:
Options
- A(A)-(IV), (B)-(I), (C)-(II), (D)-(III)
- B(A)-(IV), (B)-(II), (C)-(I), (D)-(III)
- C(A)-(I), (B)-(IV), (C)-(II), (D)-(III)
- D(A)-(IV), (B)-(I), (C)-(III), (D)-(II)
Correct answer
A. (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
Step-by-step solution
(A) Chlorine ( Cl ) has the most negative electron gain enthalpy among all elements due to its relatively larger size than fluorine, which reduces interelectronic repulsions. (B) Sodium ( Na ) is an alkali metal and has the largest atomic size in Period 3, resulting in the lowest first ionization enthalpy in that period. (C) Argon ( Ar ) has 18 electrons. The potassium cation ( K ⁺ ) also has 19 - 1 = 18 electrons, making them isoelectronic. (D) Caesium ( Cs ) is the alkali metal with the largest atomic radius (exc