Consider ( particle,( particle and (- rays, each having an energy of 0.5 Me V. In increasing order of penetrating powers, the radiations are:
Energy of 24.6 eV is required to remove one of the electrons from a neutral helium atom. The energy in (eV) required to remove both the electrons from a neutral helium atom is
A radioactive material decays by simultaneous emission of two particles with respective half-lives 1620 and 810 years. The time, in years, after which one-fourth to the material remains is
Masses of two isobars29 Cu64Zn64 are 63.9298 u and 63.9292 u respectively. It can be concluded from these data that
Both the isobars are stable.
Zn64 is radioactive, decaying to Cu64 through
Cu64 is radioactive, decaying to Zn64 through (-decay
Cu64 is radioactive, decaying to Zn64 through (-decay.
If the atom 100Fm257 follows the Bohr model and the radius of 100Fm257 is n times the Bohr radius, then find n.
The largest wavelength in the ultraviolet region of the hydrogen spectrum is 122 nm. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is
The electron in a hydrogen atom makes a transition n1( n2 where n1 and n2 are the principal quantum numbers of the two states. Assume the Bohr model to be valid. The time period of the electron in the initial state is eight times that in the final state. The possible values of n1 and n2 are
n1 =8, n2=2
1 and 4
2 and 3