# Problem: How many unpaired electrons would you expect on aluminum in aluminum oxide.

###### FREE Expert Solution

Step 1: Recall that for a neutral element, Atomic number = # of protons = # of electrons

The atomic number of Al is 13 which means Al has 13 electrons.

The location of Al in the periodic table is shown below: Based on the figure, Al belongs in the p-block in Period 3 so its electron configuration will contain the 3s and 3p subshells

Recall that:

s–subshell can hold a maximum of 2 electrons

p–subshell can hold a maximum of 6 electrons

d–subshell can hold a maximum of 10 electrons

f–subshell can hold a maximum of 14 electrons

Starting from 1s, the electron configuration for Al is:

Al: 1s22s22p63s23p1

Step 2: In aluminum oxide, the charge of aluminum is +3.

The +3 charge means 3 e were lost. Therefore, we need to subtract 3 e starting from the highest energy level (3p).

The electron configuration for Al3+ is:

Al3+: 1s22s22p6 ###### Problem Details

How many unpaired electrons would you expect on aluminum in aluminum oxide.