On the basis of Heisenbergs uncertainty principle, show that the electron cannot exist within the nucleus.

Atomic radius is the order of 10^-8 cm. and nuclear radius is the order of 10^--13 cm. Calculate what fraction of atom is occupied by nucleus

Electromagnetic radiations of wavelength 242 nm is just sufficient to ionise sodium atom. Calculate the ionisation energy of sodium in kJ mol^-1.

The shortest wave length in H spectrum of Lymen series when Rh = 109678 cm^1 is

An electron beam can undergo diffraction by crystals. Through what potential should a beam of electrons be accelerated so that its wavelength becomes equal to 1.54 A