Bohr model

$\mathbf X^{a+}$ and $\mathbf Y^{b+}$ are hydrogen-like species. The wavelength of light absorbed during the transition between the states with principal quantum numbers $n=1$ and $n=2$ of $\mathbf X^{a+}$ is $\lambda$. The wavelength of light absorbed during the transition between the states with principal quantum numbers $n=2$ and $n=4$ of $\mathbf Y^{b+}$ is $9\lambda$. The lowest possible value of $(\boldsymbol a+\boldsymbol b)$ is ____.

What is the energy (in J atom$^{-1}$) required for the following process ?
$$\ce{Li^{2+}(g) -> Li^{3+}(g) + e-}$$
(Take the ionization energy for the H atom in the ground state as $2.18\times10^{-18}$ J atom$^{-1}$)

What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?

The species having identical radii according to the Bohr's theory are:

A. H (first orbit)

B. $\ce{He+}$ (first orbit)

C. $\ce{He+}$ (Second orbit)

D. $\ce{Li^{2+}}$ (first orbit)

E. $\ce{Be^{3+}}$ (Second orbit)

Choose the correct answer from the options given below:

If shortest wavelength of hydrogen atom in Lyman series is $x$, then longest wavelength in Balmer series of $\ce{He+}$ is:

The Bohr radius of a hydrogen like species is 70.53 pm. The species and the stationary state (n) are respectively

(Given : Hydrogen atom Bohr radius is 52.9 pm)

Among the following, the correct statement(s) for electrons in an atom is(are)

According to Bohr's model, the highest kinetic energy is associated with the electron in the

For $\ce{He+}$, a transition takes place from the orbit of radius 105.8 pm to the orbit of radius 26.45 pm. The wavelength (in nm) of the emitted photon during the transition is _____.

[Use: Bohr radius, $a = 52.9$ pm; Rydberg constant, $R_\mathrm{H} = 2.2\times10^{-18}$ J; Planck's constant, $h = 6.6\times10^{-34}$ J s; Speed of light, $c = 3\times10^8\ \mathrm{m\,s^{-1}}$]

The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is $x\times10^{-8}$ m. The value of $x$ is ______. (Nearest Integer)

(Given : Energy of the electron in the first shell of the hydrogen atom is $-2.2\times10^{-18}$ J; $h=6.63\times10^{-34}$ Js and $c=3\times10^8\ \mathrm{ms^{-1}}$)

If the radius of the 3$^{\rm rd}$ Bohr's orbit of hydrogen atom is $r_3$ and the radius of 4$^{\rm th}$ Bohr's orbit is $r_4$. Then :

When the excited electron of a H atom from n = 5 drops to the ground state, the maximum number of emission lines observed are ______.

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium.

Reason R: Energies of the orbitals in the same subshell decrease with increase in the atomic number.

In the light of the above statements, choose the correct answer from the options given below.

Identify the incorrect statement from the following.

If the wavelength for an electron emitted from H-atom is $3.3\times10^{-10}$ m, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is ______ times. (Nearest integer)

[Given : h = $6.626\times10^{-34}$ J s]

Mass of electron = $9.1\times10^{-31}$ kg

The figure below is the plot of potential energy versus internuclear distance $(d)$ of $\ce{H2}$ molecule in the electronic ground state. What is the value of the net potential energy $E_0$ (as indicated in the figure) in $\mathrm{kJ\,mol^{-1}}$, for $d = d_0$ at which the electron-electron repulsion and the nucleus-nucleus repulsion energies are absent? As reference, the potential energy of H atom is taken as zero when its electron and the nucleus are infinitely far apart.

Use Avogadro constant as $6.023\times10^{23}\ \mathrm{mol^{-1}}$.

The ground state energy of hydrogen atom is −13.6 eV. Consider an electronic state $\Psi$ of $\ce{He+}$ whose energy, azimuthal quantum number and magnetic quantum number are −3.4 eV, 2 and 0, respectively. Which of the following statement(s) is(are) true for the state $\Psi$?

Which of the following options has the correct combination considering List-I and List-II?

Which of the following options has the correct combination considering List-I and List-II?

For hydrogen atom, the only CORRECT combination is