# What are the quantum numbers for 5th and 6th and 7th electrons of potassium?

##### 1 Answer
Jun 14, 2018

Electronic configuration of potassium (""_19"K") is

${\text{1s"^2\ "2s"^2\ color(red)("2p"^6)\ "3s"^2\ "3p"^6\ "4s}}^{1}$

${5}^{\text{th", 6^"th"\ &\ 7^"th}}$ electrons are in $\text{2p}$ subshell. Therefore their principal quantum number ($\text{n}$) and angular momentum quantum number (ℓ) will be $2$ and $1$ respectively.

Possible magnetic quantum numbers (${\text{m}}_{l}$) of $\text{p}$-subshell are $- 1 , 0 , + 1$, where $0$ is assigned to the $z$.

Spin quantum number (${\text{m}}_{s}$) of first electron entering in an orbital is $\pm \frac{1}{2}$, since they are indistinguishable from the other one in the same orbital.

underline(bb("Electron" color(white)(...) Orbital color(white)(no..) n color(white)(......) ℓ color(white)(.........) m_l color(white)(..../...) m_s color(white)(...)))
color(white)(......)5^"th" color(white)(.............) "2p"_"x" color(white)(............) 2 color(white)(.......) 1 color(white)(.....) -1 color(white)(?.) pm1/2

color(white)(......) 6^"th" color(white)(.............) "2p"_"z" color(white)(............) 2 color(white)(.......) 1 color(white)(..........) 0 color(white)(?.) pm1/2

color(white)(......) 7^"th" color(white)(.............) "2p"_"y" color(white)(............) 2 color(white)(.......) 1 color(white)(......) +1 color(white)(?.) pm1/2