Which of the following electronic configuration is not possible?

1.	Which of the following electronic configuration is not possible?
Answer» `1s^2 2s^2 2p^6` `1s^2 2s^2 2p^7` `1s^2 2s^2` `1s^2 2s^2 2p^5` SOLUTION :`2p^7` is not POSSIBLE

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