Payload is defined as the difference between the mass of the displaced air and the mass of the balloon. Calculate the payload when a balloon of radius 10 m, mass 100 kg is filled with helium at 1.66 bar at 27°C. (Density of air = 1.2 kgm-3 and R = 0.083 bar dm3 K-1 mol-1)

The wavelength of first line of lyman series in hydrogen tom is 1216 angstrom. the wavelength of first line of lyman series for 10 times ionsied sodium atom will be