Here's how to figure that out:

* Principal Quantum Number (n): The 3rd energy level has a principal quantum number (n) of 3.

* Sublevels: The 3rd energy level has three sublevels: s, p, and d.

* Orbitals: Each sublevel contains a specific number of orbitals:

* s: 1 orbital (holds 2 electrons)

* p: 3 orbitals (holds 6 electrons)

* d: 5 orbitals (holds 10 electrons)

Total Capacity: 2 + 6 + 10 = 18 electrons