Atomic radius is the order of 10^-8 cm. and nuclear radius is the order of 10^--13 cm. Calculate what fraction of atom is occupied by nucleus

Electromagnetic radiations of wavelength 242 nm is just sufficient to ionise sodium atom. Calculate the ionisation energy of sodium in kJ mol^-1.

The shortest wave length in H spectrum of Lymen series when Rh = 109678 cm^1 is

An electron beam can undergo diffraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes equal to 1.54 A

The mass charge ratio for A+ ion is 1.97x10^-7 kg C^-1. Calculate the mass of A atom.

AIR service on Vividh Bharati is transmitted on 219 m band. What is its transmission frequency in Hertz?

Calculate the number of photon emitted in 10 hours by a 60 W sodium lamp (lemda or photon = 5893 A")

Calculate the longest wavelength which can remove the electron from first Bohrs orbit. Given E1 = 13.6 eV .

Calculate momentum of radiations of wavelength 0.33 nm.

The ionization energy of He+ is 19.6 10^-18 J atom^-1. The energy of the first stationary state of Li+2 will be :

Show that the wavelength of a 150 g rubber ball moving with a velocity 50 m sec^-1 is short enough to be observed ..

If an electron is present in n = 6 level. How many spectral lines would be observed in case of H atom ...

What arethe differance between "Nodal surface" and "Nodal plane" ?

Nodal Surface : The place find in between two "s" orbitals where the value of electron density is equal to zero called Nodal surface. 

Nodal Plane : The plane for "p" and "d" orbitals where the value of electron density is equal to zero called Nodal Plane. 

Speed of helium atom at 300K is 2.40 x10^2 meter per sec. What is its wave length. (mass number of helium is 4)..

K.E. of the electron is 4.55 x 10^-25 J. Its de Broglie wave length is ...

The wavelength associated with a golf ball weighing 200g and moving at a speed of 5m/h is of the order.

The ratio of wave length of photon corresponding to the alpha-line of Lyman series in H-atom and Beta-line of Balmer series in He+ is

The shortest wavelength of He+ ion in Balmer series is x, then longest wavelength in the Paschene series of Li+2 is

The ratio of difference in wavelengths of 1st and 2nd lines of Lyman series in H like atom to difference in wavelength for 2nd and 3rd lines of same series is:

What are Zeeman and Stark effects? Were they explained by the Bohr’s theory?

The splitting of spectral lines into many components in the presence of a magnetic field is called Zeeman effect.

Analogously, the splitting of spectral lines into many components in the presence of an electric field is called Stark effect. 

These effects could not be explained within the framework of Bohr's theory and required the presence of multiple non-circular orbits corresponding to each energy level. An effort, with some degree of success, was made by Sommerfeld to explain these phenomena by invoking multiple elliptical orbits corresponding to each energy level. The Bohr Sommerfeld theory was ultimately discarded along with Bohr's model for other reasons.