🤓 Based on our data, we think this question is relevant for Professor Chen's class at CSULB.

We’re being asked to **determine the number of orbitals** contained in the **third principal level (n = 3)**.

Recall that the ** quantum numbers** that define an electron are:

• *Principal Quantum Number* **(n)**: deals with the size and energy of the atomic orbital.

The possible values for n are **1 to ∞**.

• *Angular Momentum Quantum Number ***(l)**: deals with the shape of the atomic orbital.

The possible values for l are **0 to (n – 1)**.

• *Magnetic Quantum Number ***(m _{l})**: deals with the orientation of the atomic orbital in 3D space.

The possible values for m_{l} are the range of l: **–l to +l**.

How many orbitals are contained in the third principal level (n=3) of a given atom?

A) 7

B) 5

C) 9

D) 3

E) 18