Which two orbitals are located along the axes and not between the axes?

The number of correct statements from the following:
$A.$ For $1s$ orbital,the probability density is maximum at the nucleus.
$B.$ For $2s$ orbital,the probability density first increases to maximum and then decreases sharply to zero.
$C.$ Boundary surface diagrams of the orbitals enclose a region of $100\%$ probability of finding the electron.
$D.$ $p$ and $d$-orbitals have $1$ and $2$ angular nodes respectively.
$E.$ Probability density of $p$-orbital is zero at the nucleus.

The quantum number which specifies the location of an electron as well as energy is

An ion has $18$ electrons in the outermost shell,it is

Which of the following combination of statements is true regarding the interpretation of the 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 peak shifting towards higher $r$ values.

The orientation of an atomic orbital is governed by