# What does the superscript represent in electron configuration notation?

##### 1 Answer
Oct 30, 2016

The superscript represents the number of electrons in that particular orbital sublevel (it does not represent an element inside an orbital).

For example,

$1 {s}^{\textcolor{red}{2}} 2 {s}^{\textcolor{red}{2}} 2 {p}^{\textcolor{red}{5}}$ tells us that there are:

• $2$ electrons in the core $1 s$ orbital of $\text{F}$
• $2$ electrons in the core $2 s$ orbital of $\text{F}$
• $5$ total electrons combined in the $2 {p}_{x}$, $2 {p}_{y}$, and $2 {p}_{z}$ valence orbitals of $\text{F}$.

$\text{ "ul(uarrdarr)" "ul(uarrdarr)" } \underline{\uparrow \textcolor{w h i t e}{\downarrow}}$
" "underbrace(" "" "" "" "" "" "" "" ")
$\text{ "" "" "" }$ $2 p$

$\underline{\uparrow \downarrow}$
"" $2 s$
$\text{ }$
$\text{ }$
$\text{ }$
$\text{ }$
$\text{ }$
$\text{ }$
$\text{ }$
$\text{ }$
$\underline{\uparrow \downarrow}$
"" $1 s$

The total number of electrons tells us that for a neutral element, the atomic number is equal to that number, telling us the identity of the element in question (assuming neutrality).

Thus, I knew it was $\text{F}$ if I assumed it was neutral and found that obviously, $2 + 2 + 5 = 9$, as this is the atomic number of $\text{F}$.

(Of course, it could have also been ${\text{O}}^{-}$, or ${\text{Ne}}^{+}$, but those are significantly less realistic.)