In an atom there are p photons, n neutrons and e electrons. For atoms of small mass, the relation between pn and e is   


Correct option is

For light elements, the number of neutrons is almost equal to the number of protons. The number of electrons, in all atoms, equals the number of protons.



In terms of the Rydberg’s constant R, the minimum wavelength in the Lyman series is  


The wavelength of the second line of Balmer series is 486.4 nm. What is the wavelength of the first line of Lyman series?


The wavelength of the first line in Balmer series in the hydrogen spectrumis . What is the wavelength of the second line. 


The energy needed to ionize the hydrogen atom in the first excited state is 3.4 eV. What is the ionization potential of hydrogen in the ground state?


The ionization energy of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by electromagnetic radiation of energy 12.1 eV. How many spectral lines will be emitter by the hydrogen atom?


If an orbital electron of the hydrogen atom jumps from the ground state to a higher energy state, its orbital speed reduces to half its initial value. If the radius of the electron orbit in the ground state is r, then the radius of the new orbit would be  


The orbital speed of the electron in the ground state of hydrogen is v. What will be its orbital speed when it is excited to the energy state –3.4eV. 


The ratio of the wavelengths of the longest wavelength lines in the Lyman and Balmer series of hydrogen spectrum is 


If a hydrogen atom at rest, emits a photon of wavelength , the recoil of the atom of mass m is given by


Cal to protons ever attract each other?