If the $Aufbau$ rule were not followed,then $Ca$ would belong to which block?

The last orbit of argon would have how many electrons?

Which of the following combinations of statements is true regarding the interpretation of atomic orbitals?
$1$. An electron in an orbital of high angular momentum stays further away from the nucleus than an electron in an orbital of lower angular momentum.
$2$. For a given value of the principal quantum number, the size of the orbit is inversely proportional to the azimuthal quantum number.
$3$. According to wave mechanics, the ground state angular momentum is equal to $\frac{h}{2\pi}$.
$4$. The plot of $\Psi$ vs $r$ for various azimuthal quantum numbers shows the peak shifting towards higher $r$ values.

For a sodium atom,the number of electrons with $m = 0$ will be:

An electron having the quantum numbers $n = 4, l = 3, m = 0, s = -\frac{1}{2}$ would be in the orbital

Select the odd one among the following orbitals based on the $(n+l)$ rule.