Identify the correct statement.

Which of the following configurations follows Hund's rule?

The orbital angular momentum of an electron in $2s$-orbital is

The quantum numbers of six electrons are given below. Arrange them in order of increasing energy. If any of these combinations have the same energy,list them:
$(1)$ $n = 4, l = 2, m_l = 2, m_s = -1/2$
$(2)$ $n = 3, l = 2, m_l = 1, m_s = +1/2$
$(3)$ $n = 4, l = 1, m_l = 0, m_s = +1/2$
$(4)$ $n = 3, l = 2, m_l = -2, m_s = -1/2$
$(5)$ $n = 3, l = 1, m_l = -1, m_s = +1/2$
$(6)$ $n = 4, l = 1, m_l = 0, m_s = +1/2$

Which statement is true regarding the hydrogen atom?

Match the entries in Column $I$ with the correctly related quantum number$(s)$ in Column $II$.

Column $I$	Column $II$
$A$. Orbital angular momentum of the electron in a hydrogen-like atomic orbital	$p$. Principal quantum number
$B$. $A$ hydrogen-like one-electron wave function obeying Pauli principle	$q$. Azimuthal quantum number
$C$. Shape, size and orientation of hydrogen-like atomic orbitals	$r$. Magnetic quantum number
$D$. Probability density of electron at the nucleus in hydrogen-like atom	$s$. Electron spin quantum number