The element with the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$ is

An element in $+2$ oxidation state has $24$ electrons. The atomic number of the element and the number of unpaired electrons in it respectively are

Maximum number of electrons possible with spin quantum number $+\frac{1}{2}$ with principal quantum number $n=4$ in an atom is

Which of the following statements are true?
$(A)$ The subsidiary quantum number $\ell$ describes the shape of the orbital occupied by the electron.
$(B)$ The image shows the boundary surface diagram of the $2p_x$ orbital.
$(C)$ The $+$ and $-$ signs in the wave function of the $2p_x$ orbital refer to charge.
$(D)$ The wave function of the $2p_x$ orbital is zero everywhere in the $yz$ plane.

$A$: No two electrons in an atom can have the same set of all four quantum numbers.
$R$: Two electrons in an atom can exist in the same shell,subshell,or orbital only if they have opposite spins.

Which of the following are degenerate orbitals?
$3d_{xy}, 4d_{xy}, 3d_{z^2}, 3d_{xz}, 4d_{yz}, 4d_{z^2}$