Identify the element if its expected electronic configuration is $[Ar] 3d^{10} 4s^{2}$.

What is the decreasing order of energy for the $2s$-orbital of $H, Li, Na$,and $K$ atoms?

How many orbitals are present in a $g$ subshell?

Maximum number of electrons that can be accommodated in the subshell with azimuthal quantum number $l=4$ is

$(i)$ An atomic orbital has $n=3$. What are the possible values of $l$ and $m_l$?
$(ii)$ List the quantum numbers ($m_l$ and $l$) of electrons for $3d$ orbital.
$(iii)$ Which of the following orbitals are possible? $1p$,$2s$,$2p$,and $3f$.

In Niobium $(Z = 41)$,the number of electrons with $m = -1$ will be: