Atoms

During the transition of electron from state A to state C of a Bohr atom, the wavelength of emitted radiation is 2000 and it becomes 6000 when the electron jumps from state B to state C. Then the wavelength of the radiation emitted during the transition of electrons from state A to state B is

1. 4000
2. 6000
3. 2000
4. 3000

An electron in the ground state of the hydrogen atom has the orbital radius of 5.3 10-11 m while that for the electron in third excited state is 8.48 10-10 m. The ratio of the de Broglie wavelengths of electron in the ground state to that in the excited state is

1. 4
2. 3
3. 9
4. 16

A hydrogen atom in ground state is given an energy of 10.2 eV. How many spectral lines will be emitted due to transition of electrons?

1. 3
2. 6
3. 10
4. 1

In an alpha particle scattering experiment distance of closest approach for the particle is 4.5 10-14 m. If target nucleus has atomic number 80 , then maximum velocity of -particle is 105 m/s approximately. ( 14 0 = 9 109 SI unit, mass of particle = 6.72 10-27 kg)

The ratio of the shortest wavelength of Balmer series to the shortest wavelength of Lyman series for hydrogen atom is :

1. 1 : 2
2. 1 : 4
3. 2 : 1
4. 4 : 1

Radius of a certain orbit of hydrogen atom is 8.48 Å. If energy of electron in this orbit is E/x, then x = (Given a0 = 0.529 Å, E = energy of electron in ground state).

The longest wavelength associated with Paschen series is : (Given RH = 1.097 107 SI unit)

1. 2.973 10-6 m
2. 1.876 10-6 m
3. 1.094 10-6 m
4. 3.646 10-6 m

In Franck-Hertz experiment, the first dip in the current-voltage graph for hydrogen is observed at 10.2 V. The wavelength of light emitted by hydrogen atom when excited to the first excitation level is nm. (Given hc = 1245 eV nm, e = 1.6 10-19 C).

An electron rotates in a circle around a nucleus having positive charge Ze. Correct relation between total energy (E) of electron to its potential energy (U) is :

1. 2E = 3U
2. E = U
3. 2E = U
4. E = 2U

The angular momentum of an electron in a hydrogen atom is proportional to : (Where r is the radius of orbit of electron)

1. 1r
2. 1 r
3. r
4. r