# How do you write the noble-gas electron configuration for potassium?

May 30, 2018

$\text{Electronic configuration of potassium} \equiv \left[A r\right] 4 {s}^{1}$

#### Explanation:

For $\text{potassium}$, $Z = 19$....and so for the full electronic configuration we write...

$1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{1}$

But we can abridge this slightly...

${\underbrace{1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6}}}_{\text{configuration of argon, Z=18}} 4 {s}^{1}$

And finally we get...$\ldots K : \left[A r\right] 4 {s}^{1.} \ldots$