$A$ certain electronic transition from an excited state to the ground state of the $H$ atom in one or more steps gives rise to four lines in the ultraviolet region of the spectrum. How many lines does this transition produce in the infrared region of the spectrum?

As an electron is brought from an infinite distance close to the nucleus of the atom,the energy of the electron-nucleus system :

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

The difference in wavelength of first and second spectral lines of Lyman series in $Li^{2+}$ ion spectrum is ................ $\mathring{A}$

The hydrogen spectrum consists of several spectral lines in the Lyman series ($L_1, L_2, L_3 \ldots$; $L_1$ has the lowest energy among the Lyman series). Similarly,it consists of several spectral lines in the Balmer series ($B_1, B_2, B_3 \ldots$; $B_1$ has the lowest energy among the Balmer lines). The energy of $L_1$ is $x$ times the energy of $B_1$. The value of $x$ is . . . . . . $\times 10^{-1}$ (Nearest integer).

Which of the following provisions of the Bohr atomic model of hydrogen turned out to be false?