* Energy Levels: The first two energy levels are filled, meaning they contain their maximum number of electrons:

* Level 1 (n=1): 2 electrons (1s²)

* Level 2 (n=2): 8 electrons (2s² 2p⁶)

* Third Level: The third energy level has 5 electrons.

* Level 3 (n=3): 5 electrons (3s² 3p³)

Putting it together:

* The total number of electrons is 2 + 8 + 5 = 15

* Since it's a neutral atom, the number of electrons equals the number of protons.

* The element with 15 protons is Phosphorus (P).