Answer
$1s^22s^22p^63s^23p^63d^{10}4s^24p^64d^{10}5s^25p^2$
Work Step by Step
We write the electron configurations, using the information that we learned over the course of the chapter. Recall, we start at 1s and move up:
$1s^22s^22p^63s^23p^63d^{10}4s^24p^64d^{10}5s^25p^2$
