Question

Can an electron have a quantum number values as $n=2,l=2$ and $m=+2$?

Answer 1

For a corresponding value of principal quantum number$\left(n\right)$, the azimuthal quantum number$\left(l\right)$ ranges from $0$ to $(n-1)$. The values of magnetic quantum number$\left(m\right)$ is governed by values of $l$ it can have value between $-l$ and $+l$ through zero.

Therefore, for $n=2$ corresponding value of $l$ ranges from $l=0$ and $l=1$ and magnetic quantum number ranges from $m=-1$ to $m=+1$.

Hence, an electron cannot have values $n=2$, $l=2$ and $m=+2$