Answer
Phosphorous
Work Step by Step
Add the superscripts. The name of the element can be identified with the number of protons. The sum of superscripts corresponds to the number of electrons and since in a neutral atom the number of electrons and protons is the same, that tells us the name of the element. In this electronic configuration, the sum of super scripts ($1s^22s^22p^63s^23p^3$) is 15 and the element with 15 protons is Phosphorous.
