6.Which of the following transitions in a hydrogen atom emits the photons of highest frequency ?

7.Ratio of energy of the hydrogen atom in its first and third excited state will be

8.Ratio of nuclear radii of Au-197 and Ag-107 is

9.Half-life period of a radioactive element X is same as the mean-life time of another radioactive element Y. If initially both have same number of atoms, then

10.If a proton is completely converted into energy, then energy released will be about