Using the periodic table, indicate which element would have each of the following properties. If more than one element is possible, only list the one with the smallest atomic number:

(a) has exactly two unpaired electrons with an l = 1:

(b) has exactly three electrons with n = 5, l = 2:

We are asked to** identify the smallest atomic number element **that fits the criteria below:

**(a) has exactly two unpaired electrons with an l = 1:**

**(b) has exactly three electrons with n = 5, l = 2:**

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

• *Spin Quantum Number ***(m _{s})**: deals with the spin of the electron. The possible values for m

Quantum Numbers