Chemistry: The Central Science (13th Edition)

Published by Prentice Hall
ISBN 10: 0321910419
ISBN 13: 978-0-32191-041-7

Chapter 6 - Electronic Structure of Atoms - Exercises: 6.79a

Answer

After completely filling the $2s$ subshell, the electrons must occupy the next lowest-energy subshell, which is the $2p$ subshell and not the $3s$ one.

Work Step by Step

$1s^22s^23s^1$ As we have learned, the electrons would try to occupy the subshell with the lowest possible energy for maximum stability. - After the orbital in $1s$ subshell is completely filled with 2 electrons, the electrons move to the next lowest-energy subshell, which is the $2s$ subshell. Until now, things are correct. - After the orbital in $2s$ subshell is completely filled with 2 electrons, however, the next lowest-energy subshell that the electrons will occupy is the $2p$ subshell, not the $3s$ subshell. - Therefore, the correct configuration must be $1s^22s^22p^1$.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.