The total energy of the electron in the first excited state of hydrogen is –3.4 eV. What is the kinetic energy of the electron in this state?
The kinetic and potential energies of an electron in the nth excited state are given by
adding (i) and (ii) we get the total energy E which is
Notice from (i) and (iii) that E = –KE. Given E = –3.4 eV.
Hence KE = –E = –(–3.4) = +3.4 eV.
If the half lives of a radioactive element that decays in 6 days is 7/8. The fraction that decays in 10 days will be
The wavelength of de Broglie waves associated with an electron (massm, charger e) accelerated through a potential difference of V is given by (his Planck’s constant)
A proton, when accelerated through a potential difference of V volts, has a wavelength associated with it. If an alpha particle ius to have the same wavelength , it must be accelerated through a potential difference of
A proton and an electron move with the same velocity. The associated wavelength for proton is
Two particles of masses m and 2m have equal kinetic energies. Their de Broglie wavelength are in the ratio of
The wavelength of de Broglie wave associated with a thermal neutron of mass m at absolute temperature T is given by (here k is the Boltzmann constant)
The momentum of a photon of frequency v is
Which energy state of the triply ionized beryllium (Be+++) has the same electrons orbital radius as that of the ground state of hydrogen? Given Zfor beryllium = 4.
Which energy state of doubly ionized lithium (Li++) has the same energy as that of the ground state of hydrogen? Given Z for lithium = 3.
The energy of the electron of hydrogen orbiting in the stationary orbit of radius rn is proportional to