A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. What series of wavelength will be emitted ?

Calculate the energy required to remove an electron completely from n = 2 orbit of hydrogen atom, What is the longest wavelength of light in cm that can be used to cause this transition?

The energy of separation of an electron in a Hydrogen like atom in excited state is 3.5 eV. The de-Broglie wave length (in Å) associated with the electron is: (Given radius of I orbit of hydrogen atom is 0.53 Å)

A balloon is filled with hydrogen at room temperature. It will burst if pressure exceeds 0.2bar. If at 1bar pressure the gas occupies 2.27 L volume, upto what volume can the ballon be expanded?

The total energy of an electron in ground state of hydrogen atom is -13.6eV. What is the signifi cance of negative sign?