Henry Moseley studied the characteristic $X$-ray spectra of elements. The graph which represents his observation correctly is: (Given $\nu =$ frequency of $X$-ray emitted; $Z =$ atomic number)

The total energy of an atomic electron is :

The energy of the second excited state of the $Li^{2+}$ ion is ............... $eV$.

If $m$ and $e$ are the mass and charge of the revolving electron in the orbit of radius $r$ for a hydrogen atom,the total energy of the revolving electron will be:

The ionization energy of a hydrogen atom is $13.6 \ eV$. The energy required to excite the electron in a hydrogen atom from the ground state $(n=1)$ to the first excited state $(n=2)$ is (Note: The question asks for energy per atom in Joules. Given $1 \ eV = 1.602 \times 10^{-19} \ J$)

Which of the following electronic transitions in a hydrogen atom will require the largest amount of energy?