To which block does an element with the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$ belong in the periodic table?

Five valence electrons of $P^{15}$ are labelled as $\boxed{AB}_{3s} \,\boxed{X|Y|Z}_{3p}$. If the spin quantum numbers of $B$ and $Z$ are $+\frac{1}{2}$,the group of electrons with three of the quantum numbers $(n, l, m)$ the same are:

The four quantum numbers for the electron in the outermost orbital of potassium (atomic number $19$) are:

The valence shell electronic configuration is $(n - 1)s^2 (n - 1)p^6 (n - 1)d^x ns^2$. If $n = 4$ and $x = 5$,what is the number of protons in the element?

The magnetic quantum number for an electron when the value of principal quantum number is $2$ can have ............ values.

Find the number of electron pairs in $P$ atom with $l = 1$ and $m = 0$.