Atoms practice · Medium

The earth revolves round the sun due to gravitational attraction. Suppose that the sun and the earth are point particles with their existing masses and that Bohr's quantization rule for angular momentum is valid in the case of gravitation.

(a) Calculate the minimum radius the earth can have for its orbit.

(b) What is the value of the principal quantum number $n$ for the present radius? Mass of the earth $=6.0 \times 10^{24} \mathrm{~kg}$, mass of the sun $=2.0 \times 10^{30} \mathrm{~kg}$, earth-sun distance $=1.5 \times 10^{11} \mathrm{~m}$.

Whenever a photon is emitted by hydrogen in Balmer series, it is followed by another photon in Lyman series. What wavelength does this latter photon correspond to?

X-rays are produced in X-ray tube operating at a given accelerating voltage. The wavelength of the continuous $\mathrm{X}$-rays has values from

A particle moving with a velocity of $\frac{1}{{100}}\mathrm{th}$ of that of light will cross a nucleus on about

Let ${\lambda _\alpha },{\lambda _\beta }$ and ${{\lambda '}_\alpha }$ denote the wavelengths of the $\mathrm{X}$-rays of the ${K_\alpha },{K_\beta }$ and ${L_\alpha }$ lines in the characteristic $\mathrm{X}$-rays for a metal. Then

An X-ray tube is operated at $15 \mathrm{~kV}$. Calculate the upper limit of the speed of the electrons striking the target.

The number of different wavelengths may be observed in the spectrum from a hydrogen sample if the atoms are excited to third exited state is

If the atom $_{100}F{m^{257}}$ follows the Bohr model and radius of $_{100}F{m^{257}}$ is n time the Bohr radius, then find n

In $X$-ray tube when the accelerating voltage $V$ is halved, the difference between the wavelength of ${K_\alpha }$ line and minimum wavelength of continuous $X$-ray spectrum

If $10000\;V$ is applied across an $X$-ray tube, what will be the ratio of de-Broglie wavelength of the incident electrons to the shortest wavelength of $X$-ray produced ($\frac{e}{m}$ for electron is $1.8 \times {10^{11}}ck{g^{ - 1}}$)

Hydrogen atom excites energy level from fundamental state to n =3. Number of spectrum lines according to Bohr is

Considering Bohr's atomic model for hydrogen atom:

(A) the energy of H atom in ground state is same as energy of $\mathrm{He}^{+}$ ion in its first excited state.

(B) the energy of H atom in ground state is same as that for $\mathrm{Li}^{++}$ ion in its second excited state.

(C) the energy of H atom in its ground state is same as that of $\mathrm{He}^{+}$ ion for its ground state.

(D) the energy of $\mathrm{He}^{+}$ ion in its first excited state is same as that for $\mathrm{Li}^{++}$ ion in its ground state.

Choose the correct answer from the options given below:

The ratio of energies of first two excited states hydrogen atom is

In Bohr's model of the hydrogen atom, the pairs of quantities that are quantized among the following is

Hydrogen atom excites energy level from fundamental state to n =3. Number of spectrum lines according to Bohr is

In the spectrum of single ionised helium, the wavelength of a line observed is almost the same as the first line of Balmer series of hydrogen. It is due to transition of electron.

The waves emitted when a metal target is bombarded with high energy electrons are

The wavelength of $X$-rays is

The difference between longest wavelength line of the Balmer series and shortest wavelength line of the Lyman series for a hydrogenic atom (Atomic number $Z$) equal to $\Delta \lambda$. The value of the Rydberg constant for the given atom is:

In $X$-ray tube the accelerating potential applied at the anode is $V$ volt. The minimum wavelength of the emitted $x-r a y$ will be

If the shortest wavelength of Paschen series is given by $\lambda,$ then the longest wavelength of Lyman series will be:

Statement-I: The trajectory traced by an incident particle depends on the impact parameter of collisions.

Statement-II: The impact parameter is the perpendicular distance of the initial velocity vector of the incident particle from the centre of the target nucleus.

Maximum wavelength in Balmer series of hydrogen spectrum is (R : Rydberg constant)

A positive hydrogen like ion having electron at its ground state emits it, if a photon of wavelength $228 \mathop {\text{A}}\limits^{\text{o}}$ or less is absorbed by it. Identify the ion.

Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom?

Assertion (A): In Rutherford experiment only few $\alpha-$ particles get rebounded.

Reason (R): Most of the atomic space is empty.

In hydrogen atom, for which transition minimum energy is emitted?

The value of structure constant is

Find the largest and shortest wavelengths in the Lyman series for hydrogen. In what region of the electromagnetic spectrum does each series lie?

The potential difference applied to an $X$-ray tube is increased. As a result, in the emitted radiation