1) In hydrogen, the transition from level 2 to level 1 has a rest wavelength of 121.6 nm.
Find the speed for a star in which this line appears at wavelength 120.8 nm .

3) Find the speed for a star in which this line appears at wavelength 121.1 nm ..

5) Find the speed for a star in which this line appears at wavelength 121.8 nm .

7)Find the speed for a star in which this line appears at wavelength 122.4 nm .