MCQ
Which electronic configuration must represent an atom in an excited state?
- A$1s^2 ,2s^2 2p^1$
- B$1s^2 ,2s^2 2p^2$
- ✓$1s^2 ,2s^22p^2 ,3s^1$
- D$1s^2 ,2s^2 2p^5$
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Reason : In presence of $H_2SO_4$, $HNO_3$ acts as a base and produces $NO_2^+$ ions.
