In the Balmer series of the hydrogen atom spectrum,which electronic transition causes the third line?

The energy of an electron in the first Bohr orbit of the $H$ atom is $-13.6 \, eV$. The energy value of an electron in the first excited state of the $H$ atom is ............ $eV$.

In the hydrogen spectrum,if an electron transitions from the $6^{th}$ orbit to the $3^{rd}$ orbit,what is the total number of spectral lines observed in the infrared region?

The energy of an electron in the $3^{rd}$ orbit of a hydrogenic atom is $-E$. The energy of an electron in the first orbit will be

In which one of the following pairs of experimental observations and phenomena does the experimental observation correctly account for the phenomenon?

In $He^{+}$ ion,the energy of $2^{nd}$ orbit is $-13.6 \ eV/atom$. The kinetic energy of the same orbit for $He^{+}$ ion will be: