JEE Chemistry 2025 Question with Solution

Given: Statements A to E about electron affinity, ionization energy, electronegativity, and electropositivity are to be checked.

Find: Which statements are correct and the corresponding option.

1. Statement A: Adding an electron to a neutral gaseous atom is not always exothermic; for some atoms it can be endothermic. So A is incorrect.

2. Statement B: Removing an electron from an isolated gaseous atom always requires energy. Therefore, this process is always endothermic. So B is correct.

3. Statement C:

In Be, the $2s$ subshell is fully filled, so more energy is needed to remove an electron than in B. Therefore, the first ionization energy of boron is less than that of beryllium. So C is correct.

4. Statement D: In the extracted solution, carbon in $CCl_4$ is considered to have higher effective nuclear attraction than in $CH_4$, so the electronegativity is not taken as the same in both. Hence D is incorrect according to the solution working.

5. Statement E: The most electropositive alkali metal is not Li; the solution states Cs is most electropositive. So E is incorrect.

Therefore, the correct statements are B and C only. The correct option is A.

Given: A set of periodic property statements.

Find: The true statements.

• Electron addition is not invariably energy-releasing, so statement A fails.
• Ionization always involves supplying energy to remove an electron from an isolated gaseous atom, so statement B is true.
• Because Be has a filled $2s$ subshell while B loses a $2p$ electron, boron has lower first ionization enthalpy, so statement C is true.
• The provided solution rejects statement D by comparing carbon in $CH_4$ and $CCl_4$.
• Electropositivity increases down group $1$, so Li cannot be the most electropositive; statement E is false.

Thus only B and C are correct, which matches option A.