The wavenumber associated with the maximum energy in the Balmer series will be......

The maximum energy is possessed by an electron when it is present:

The energy of an electron in the $3^{rd}$ orbit of $H$-atom (in $J$) is approximately:

The statements
$i$. In filling a group of orbitals of equal energy,it is energetically preferable to assign electrons to empty orbitals rather than pair them into a particular orbital.
$ii$. When two electrons are placed in two different orbitals,energy is lower if the spins are parallel.
Are valid for

The element used by Rutherford in his famous scattering experiment was

The light of wavelength $242 \, nm$ is required to remove an electron from a $Na$ atom. What is the ionization energy of the sodium atom in $kJ \, mol^{-1}$?