# Question #54a62

##### 1 Answer
Jan 16, 2016

$K r : 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10} 4 {p}^{6}$ and $X e : 1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 4 {s}^{2} 3 {d}^{10} 4 {p}^{6} 5 {s}^{2} 4 {d}^{10} 5 {p}^{6}$

#### Explanation:

If you want to do the long (and exhausting, I might add) electronic configuration of big numbered elements you just have to go through the electron configuration model until you reached the total number of electrons of the desired element, Krypton and Xenon in this case.

But if you want it to be hassle free and simplified, you can just write down the previous noble gas and add the remaining configuration. In this case, $K r : \left[A r\right] 4 {s}^{2} 3 {d}^{10} 4 {p}^{6}$ and $X e : \left[K r\right] 5 {s}^{2} 4 {d}^{10} 5 {p}^{6}$.