Atoms and Nucle...

In a hypothetical Bohr hydrogen, the mass of the electron is doubled. The energy E₀ and the radius r₀ of the first orbit will be (a₀ is the Bohr radius)

What is the radius of iodine atom (at. no. 53, mass number 126)?

If in Rutherford\'s experiment, the number of particles scattered at 90° angle are 28 per min, then number of scattered particles at an angle 60° and 120° will be

A double charged lithium atom is equivalent to hydrogen whose atomic number is 3. The wavelength of required radiation for emitting electron from first to third Bohr orbit in Li⁺⁺ will be (Ionization energy of hydrogen atom is 13.6 eV

The ionization potential of H–atom is 13.6 V. When it is excited from ground state by monochromatic radiations of 970.6 Å, the number of emission lines will be (according to Bohr\'s theory)

A neutron with velocity V strikes a stationary deuterium atom, its kinetic energy changes by a factor of

An electron passing through a potential difference of 4.9 V collides with a mercury atom and transfers it to the first excited state. What is the wavelength of a photon corresponding to the transition of the mercuryatom to its normal state

The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is 1.4 kilowatt/m². The average earth sun distance is 1.5 × 10¹¹metres. The mass lost by the sun per day is (1 days = 86400 seconds)

The rest energy of an electron is 0.511 MeV. The electron is accelerated from rest to a velocity 0.5 c. The change in its energy will be

The activity of a radioactive sample is measured as N₀ counts per minute at t = 0 and N₀ /e counts per minute at t = 5 minutes. The time (in minutes) at which the activity reduces to half its value is