# What is the orbital notation for the electron in an orbital with the following quantum number: n = 3, l = 1?

Oct 12, 2016

Here's what I got.

#### Explanation:

The interesting thing to notice here is that you can't really say the exact orbital in which that electron resides because you're missing the value of the magnetic quantum number, ${m}_{l}$.

As you know, four quantum numbers are used to describe the position and spin of an electron inside an atom.

The principal quantum number, $n$, describes the energy level on which the electron resides. In your case, you have

$n = 3 \to$ the third energy level

The angular momentum quantum number, $l$, describes the subshell in which the electron is located. You have

• $l = 0 \to$ the s subshell
• $l = 1 \to$ the p subshell
• $l = 2 \to$ the d subshell
• $\vdots$

In your case, the electron is located in the $p$ subshell. Now, the $p$ subshell contains a total of $3$ orbitals as described by the magnetic quantum number, ${m}_{l}$

• ${m}_{l} = \textcolor{w h i t e}{-} 0 \to$ the ${p}_{z}$ orbital
• ${m}_{l} = - 1 \to$ the ${p}_{x}$ orbital
• ${m}_{l} = + 1 \to$ the ${p}_{z}$ orbital

In order to be able to specify the exact orbital in which the electron resides, you need to know the value of ${m}_{l}$. Since that is not given to you, all you can say is that

$n = 3 , l = 1$

The electron is located on the third energy level, in the p subshell.