Chemistry Q58 – JEE-MAIN 2025

Home Chemistry Periodicity & ElementsQuestion #531

Electronic configuration of four elements A, B, C and D are given below : (A)

1 s^{2} 2 s^{2} 2 p^{3}

(B)

1 s^{2} 2 s^{2} 2 p^{4}

(C)

1 s^{2} 2 s^{2} 2 p^{5}

(D)

1 s^{2} 2 s^{2} 2 p^{2}

Which of the following is the correct order of increasing electronegativity (Pauling's scale) ?

Clue 1 of 3: Identify the elements

Determine the atomic number and thus the element name for each given electronic configuration.

🥷

Ninja Strategy•Identify Extremes

Quickly identify the least and most electronegative elements (D and C, respectively) and check which option correctly places them at the beginning and end of the increasing order.

🧠 Full Solution Path

Step 1: Identify the elements from their electronic configurations✦ Active

The given electronic configurations correspond to the following elements:

\begin{array}{ll} A: 1 s^{2} 2 s^{2} 2 p^{3} & ⟹ Nitrogen (N), Atomic number = 7 B: 1 s^{2} 2 s^{2} 2 p^{4} & ⟹ Oxygen (O), Atomic number = 8 C: 1 s^{2} 2 s^{2} 2 p^{5} & ⟹ Fluorine (F), Atomic number = 9 D: 1 s^{2} 2 s^{2} 2 p^{2} & ⟹ Carbon (C), Atomic number = 6 \end{array}

All these elements belong to the second period of the periodic table.

Step 2: Recall the trend of electronegativity across a period○ Expand

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. According to Pauling's scale, electronegativity generally increases across a period from left to right due to increasing nuclear charge and decreasing atomic size.

💡 Teacher's Secret Hint

Remember that Fluorine (F) is the most electronegative element.

Step 3: Order the elements by increasing electronegativity○ Expand

Based on their positions in the second period (increasing atomic number from left to right), the order of increasing electronegativity is:

Carbon (D) < Nitrogen (A) < Oxygen (B) < Fluorine (C)

Therefore, the correct order is $D < A < B < C$ .

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Chemistry Question 58 – JEE-MAIN 2025

Clue 1 of 3: Identify the elements

🧠 Full Solution Path