The Kinetic Energy Of A 300 K Thermal Neutron Is

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

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

Cal to protons ever attract each other?

How much energy is released when one amu is wholly converted into energy?

In the equation     

           ,  

The correct symbol for X is

The energy released by the fission of one uranium atom is 200 MeV. The number of fissions per second required to produce 3.2 W of power is