The fact that photons carry energy was established by

An ionic atom equivalent to hydrogen atom has wavelength equal to 1/4 of the wavelengths of hydrogen lines. The ion will be 

The third line of Balmer series of an ion equivalent to hydrogen atom has wavelength of 108.5 nm. The ground state energy of an electron of this ion will be 

Hydrogen atom emits blue light when it changes from n = 4 energy level to the n = 2 level. Which colour of light would the atom emit when it changes from the n = 5 level to the n = 2 level 

The first line of Balmer series has wavelength 6563 Å. What will be the wavelength of the first member of Lyman series

The wavelength of the energy emitted when electrons come from the fourth orbit to the second orbit in hydrogen is 20.397 cm. The wavelength of energy for the same transition in ${\mathrm{He}}^{+}$ is:

Minimum excitation potential of Bohr's first orbit in hydrogen atom is

Which of the following statements are true regarding Bohr's model of hydrogen atom?

(I) Orbiting speed of electron decreases as it shifts to discrete orbits away from the nucleus

(II) Radii of allowed orbits of electron are proportional to  principal quantum number

(III) Frequency with which electrons orbits around the nucleus in discrete orbits is inversely proportional to the cube of principal quantum number

(IV) Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits
Select correct answer using the codes given below
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 For electron moving in ${\mathrm{n}}^{\mathrm{th}}$ orbit of H-atom the angular velocity is proportional to 

Which of the following spectral series in hydrogen atom give spectral line of 4860 Å 

When an electron in hydrogen atom is excited, from its 4th to 5th stationary orbit, the change in angular momentum of electron is (Planck’s constant: h = $6.6\times {10}^{-34} \mathrm{J}-\mathrm{s}$6.6)

The concept of stationary orbits was proposed by

Who discovered spin quantum number 

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to

In Bohr’s model, if the atomic radius of the first orbit is ${\mathrm{r}}_0$, then the radius of the fourth orbit is 

If R is the Rydberg’s constant for hydrogen the wave number of the first line in the Lyman series will be

In hydrogen atom, if the difference in the energy of the electron in n =2 and n = 3 orbits is E, the ionization energy of hydrogen atom is 

The first member of the Paschen series in hydrogen spectrum is of wavelength 18,800 Å. The short wavelengths limit of Paschen series is 

The ratio of the largest to shortest wavelengths in Lyman series of hydrogen spectra is 

In Bohr model of hydrogen atom, the ratio of periods of revolution of an electron in n =2 and n = 1 orbits is

The ratio of the longest to shortest wavelengths in Brackett series of hydrogen spectra is 

Rutherford’s $\mathrm{\alpha }$-particle experiment showed that the atoms have

Which of the following is true for number of spectral lines in going from Lyman series to Pfund series ?

Radius of the first orbit of the electron in a hydrogen atom is 0.53 Å. So, the radius of the third orbit will be

The first line in the Lyman series has wavelength $\mathrm{\lambda }$. The wavelength of the first line in Balmer series is

In the following transitions, which one has higher frequency

The diagram shows the path of four $\alpha$-particles of the same energy being scattered by the nucleus of an atom simultaneously. Which of these are/is not physically possible?

An electron jumps from 5th orbit to 4th orbit of hydrogen atom. Taking the Rydberg constant as  ${10}^7$ per metre. What will be the frequency of radiation emitted

Four lowest energy levels of H-atom are shown in the figure. The number of possible emission lines would be

The wavelength of light emitted when an electron jumps from second orbit to first orbits in a hydrogen atom is