Question

Which among the following oxides of nitrogen, the nitrogen atom contains one unpaired electron?

• A. \( \mathrm{N_2O_4} \)
• B. \( \mathrm{NO_2} \)
• C. \( \mathrm{N_2O_5} \)
• D. \( \mathrm{N_2O_3} \)

Hint:

Odd-electron molecules are always paramagnetic due to unpaired electrons.

Answer 1

The Correct Option is B

Step 1: Understanding unpaired electrons.
A molecule having an odd number of total electrons will contain at least one unpaired electron and will be paramagnetic in nature.

Step 2: Electron count in \( \mathrm{NO_2} \).
Nitrogen has 7 electrons and oxygen has 8 electrons each. The total number of electrons in \( \mathrm{NO_2} \) is odd, leading to the presence of one unpaired electron.

Step 3: Analysis of other options.
All other oxides listed have even numbers of electrons and therefore do not contain unpaired electrons.

Step 4: Conclusion.
Thus, \( \mathrm{NO_2} \) is the correct answer.